What metal melts in your hand

How does a welding machine work?

A welding machine is a machine that allows you to fix the connection of two materials. The connection is achieved by melting both materials or a feed material can be added which, when melted, is placed between the parts to be welded and when cooled becomes a fixed connection.

The welding machine typically bonds metals or thermoplastic materials. The energy source for welding can be gas, electric arc, laser or ultrasound. - more details on the website

Why do you need a welding machine?

Welding machines are most often found in the industrial sector, in those industries where materials, parts, tools or metal machines are produced.

Likewise, it is very likely to find a welding machine in any home as we often have to do household tasks where we need to join two metals together.

Types of Welding Machines

There are different types of welding machines depending on what you want to use them for.

Arc welder

This is the most popular type of welder today. This machine uses electrical energy , which creates an electric arc between the metal being welded and the electrode being used. There are different types depending on the electrode used.

• Manual metal arc welding
• Metal arc gas welding
• Arc welding with molten core
• Tungsten Gas Arc Welding
• Submerged arc welding

Tin soldering iron

Delicate work and repairs to small appliances are highly recommended Very used in electronics. This machine consists of a copper tip which is heated by electrical energy and melts.

Gas soldering iron

Used when welding copper or aluminum materials. These machines use flammable gas which makes it friction to produce a flame which melts the metal input. The molten material is placed into a joint, which leaves a cord when cooled.

Laser welder

They heat the area to be welded and then apply pressure, ensuring high precision. They are very useful for joining small areas and very quickly, making them useful for mass production as well.

Soldadores Inverter

This is the latest in soldier technology. They can make different types of welds without changing the equipment. In addition, they have the advantage that they are easy to carry, have a long service life, and the visible welds are more aesthetically pleasing than other machines.

As we have seen in the previous paragraphs, there are many types of welding machines, each used to perform different tasks. But they all base their functioning on the same form of work.

Welding machines require a power source (electrical, combustion, mechanical) to convert it into energy that allows the creation of a fusion of material that is used to join two or more elements.

As we mentioned above, these machines process a lot of energy in the form of heat to melt the materials for feeding. That is why it is necessary to take into account all the safety measures necessary to use these machines without risk to humans.

Welding machine parts

For the welding machine to operate properly, it must consist of a number of parts , which we will consider in detail below.

• Welding machine: It is responsible for converting the energy source into the type of energy required to perform the welding process.
• Electrode Holder Cable: This cable extends from the welding machine winding onto the workpiece.
• Ground Wire: This wire is connected to the part where the electrode is located.
• Current selector knob - select the current strength with which the work was performed.
• On/Off button: Turns the welding machine on and off.

How to perform basic step-by-step welding

Source: https://topnewsrussia.ru/19/01/2020/26105/kak-rabotaet-svarochnyj-apparat.html

Gallium is a metal that melts in your hands

Gallium is a metal that melts in the hand. The substance has a melting point of 29.76 °C. If you place it in a warm palm, it gradually begins to change from solid to liquid form.

A brief excursion into history

What is the name of the metal that melts in your hand? As noted above, such a material is known as gallium. Its theoretical existence was predicted back in 1870 by a domestic scientist, the author of the table of chemical elements, Dmitry Mendeleev. The basis for the emergence of such an assumption was his study of the properties of numerous metals. At that time, not a single theorist could have imagined that the metal that melts in the hands exists in reality.

The possibility of synthesizing an extremely fusible material, the appearance of which Mendeleev predicted, was proven by the French scientist Emile Lecoq de Boisbaudran. In 1875, he succeeded in isolating gallium from zinc ore. During experiments with the material, the scientist obtained a metal that melts in his hands.

It is known that Emile Boisbaudran experienced significant difficulties in isolating a new element from zinc ore. During his first experiments, he managed to extract only 0.1 grams of gallium. However, even this was enough to confirm the amazing property of the material.

Where is gallium found in nature?

Gallium is one of the elements that does not occur as ore deposits. The material is very dispersed in the earth's crust. In nature, it is found in extremely rare minerals such as gallite and zengeite. During laboratory experiments, a small amount of gallium can be isolated from the ores of zinc, aluminum, germanium, and iron. Sometimes it is found in bauxite, coal deposits, and other mineral deposits.

How to obtain gallium

Currently, scientists most often synthesize the metal, which melts in the hands, from aluminum solutions that are mined during the processing of alumina. As a result of removing the bulk of aluminum and carrying out the procedure of repeated concentration of metals, an alkaline solution is obtained, which contains a small proportion of gallium. Such material is isolated from solution by electrolysis.

Areas of application

Gallium has not yet found application in industry. This is due to the widespread use of aluminum, which has similar properties in solid form. Despite this, gallium looks like a promising material because it has excellent semiconductor properties.

This metal can potentially be used for the production of transistor elements, high-temperature current rectifiers, and solar panels.

Gallium looks like an excellent solution for making optical mirror coatings that will have the highest reflectivity.

The main obstacle to the use of gallium on an industrial scale remains the high cost of its synthesis from ores and minerals. The price per ton of such metal on the world market is more than $1.2 million.

To date, gallium has found effective use only in the medical field. The metal in liquid form is used to slow down bone loss in people suffering from cancer. It is used to quickly stop bleeding in the presence of extremely deep wounds on the body of victims. In the latter case, blockage of blood vessels by gallium does not lead to the formation of blood clots.

Interesting experiments with gallium

As noted above, gallium is a metal that melts in the hands. Since the temperature required for the material to transform into a liquid state is slightly more than 29 °C, it is enough to hold it in your palms. After some time, the initially solid material will begin to melt literally before our eyes.

A rather fascinating experiment can be carried out with the solidification of gallium. The presented metal tends to expand during solidification. To conduct an interesting experiment, it is enough to place liquid gallium in a glass vial. Next you need to start cooling the container.

After some time, you will notice how metal crystals begin to form in the bubble. They will have a bluish color, as opposed to the silvery tint that is characteristic of the material in its liquid state.

If cooling is continued, the crystallizing gallium will eventually rupture the glass vial.

Finally

So we found out what kind of metal melts in the hand. Today, gallium can be found on sale for conducting your own experiments. However, the material should be handled with extreme caution. Solid gallium is a non-toxic substance. However, prolonged contact with the material in liquid form can lead to the most unforeseen health consequences, including respiratory arrest, paralysis of the limbs and a person entering a coma.

Source: https://autogear.ru/article/280/807/galliy-metall-kotoryiy-plavitsya-v-rukah/

6 Surprising Substances That Defy the Laws of Physics

We can laugh at our ancestors, who considered gunpowder to be magic and did not understand what magnets are, however, even in our enlightened age, there are materials created by science, but similar to the result of real witchcraft. These materials are often difficult to obtain, but are worth it.

1. Metal that melts in your hands

The existence of liquid metals such as mercury and the ability of metals to become liquid at a certain temperature are well known. But solid metal melting in your hands like ice cream is an unusual phenomenon. This metal is called gallium.

It melts at room temperature and is unsuitable for practical use. If you place a gallium object in a glass of hot liquid, it will dissolve right before your eyes.

In addition, gallium can make aluminum very brittle - simply placing a drop of gallium on an aluminum surface is enough.

2. Gas capable of holding solid objects

This gas is heavier than air, and if you fill a closed container with it, it will settle to the bottom. Just like water, sulfur hexafluoride can withstand less dense objects, such as a tin foil boat. The colorless gas will hold the object on its surface, and it will appear that the boat is floating. Sulfur hexafluoride can be scooped out of the container with an ordinary glass - then the boat will smoothly sink to the bottom.

In addition, due to its gravity, the gas reduces the frequency of any sound passing through it, and if you inhale a little sulfur hexafluoride, your voice will sound like the ominous baritone of Dr. Evil.

3. Hydrophobic coatings

The green tile in the photo is not jelly at all, but tinted water. It is located on a flat plate, along the edges treated with a hydrophobic coating. The coating repels water and the droplets take on a convex shape. There is a perfect raw square in the middle of the white surface and the water collects there.

A drop placed on the treated area will immediately flow to the untreated area and merge with the rest of the water. If you dip a finger treated with a hydrophobic coating into a glass of water, it will remain completely dry, and a “bubble” will form around it - the water will desperately try to escape from you.

Based on such substances, it is planned to create water-repellent clothing and glass for cars.

4. Spontaneously exploding powder

Triiodine nitride looks like a ball of dirt, but appearances can be deceiving: the material is so unstable that the slightest touch of a pen is enough to cause an explosion. The material is used exclusively for experiments - it is dangerous to even move it from place to place. When the material explodes, it produces a beautiful purple smoke. A similar substance is silver fulminate - it is also not used anywhere and is only suitable for making bombs.

5. Hot ice

Hot ice, also known as sodium acetate, is a liquid that hardens upon slightest contact. With a simple touch, it instantly transforms from a liquid state into an ice-hard crystal.

Patterns are formed on the entire surface, like on windows in frosty weather; the process continues for several seconds until the entire substance “freezes.” When pressed, a crystallization center is formed, from which information about the new state is transmitted to the molecules along the chain.

Of course, the end result is not ice at all - as the name suggests, the substance is quite warm to the touch, cools very slowly and is used to make chemical heating pads.

6. Metal with memory

Nitinol, an alloy of nickel and titanium, has the impressive ability to “remember” its original shape and return to it after deformation. All it takes is a little heat. For example, you can drop warm water on the alloy, and it will return to its original shape, no matter how much it was previously distorted.

Methods for its practical application are currently being developed. For example, it would be wise to make glasses from such material - if they accidentally bend, you just need to put them under a stream of warm water.

Of course, it is unknown whether cars or anything else serious will ever be made from nitinol, but the properties of the alloy are impressive.

Source: https://www.publy.ru/post/2471

Putin and Erdogan at a conference on Libya. What will they decide in Berlin?

MOSCOW, January 19 - RIA Novosti, Galia Ibragimova. The Berlin peace conference on a settlement in Libya was prepared in far from peaceful conditions. The presidents of Russia and Turkey made a lot of efforts to bring the warring parties to the negotiating table. RIA Novosti was looking into whether this meeting could put an end to the war.

Turkey's security is in the hands of Libya

Two days before the opening of the conference, Recep Tayyip Erdogan announced that the Turkish military was about to arrive in Tripoli. According to the memorandum of mutual assistance that Ankara concluded with the Government of National Accord (GNA), the defense of Libyan cities is now the direct task of the Turks.

“By sending our contingent to Libya, we want to support the stability and legitimacy of the government of Fayez al-Sarraj. Turkey’s security begins outside its borders, and here maximum efforts are important to stabilize the situation on the southern borders,” Erdogan said.

Partial Turkish Armed Forces were transferred to the former Jamahiriya at the end of December. Syrian armed opposition fighters loyal to Ankara also volunteered to defend Libyan cities from the army of the rebel general Khalifa Haftar. There was talk then of sending more than a thousand soldiers to Libya.

After the general took the city of Sirte and began preparations for the assault on Tripoli, Sarraj needed more reinforcements for defense. There is no need to rely on the armed groups that are part of the GNA army. Most of them are formed along tribal lines and often change their position, going over to Haftar’s side. Therefore, Ankara’s help could be decisive in the battles for the Libyan capital.

Wayward Warlord

Haftar has never hidden his dislike for Erdogan. However, even Turkey's military intervention did not force the general to abandon the attack on Tripoli, and preparations are in full swing.

The military leader is betting that as he advances towards the capital, supporters of Sarraj will join the ranks of the Libyan National Army (LNA) he leads. The hostility of many Libyan factions towards Ankara, according to Haftar’s calculations, will sooner or later prevail over their loyalty to the GNA.

Turkey's military assistance to Sarraj's government does not bother the general. So far it does not outweigh the assistance provided to him from Egypt, the UAE, and Saudi Arabia. Interaction with Moscow also strengthens Haftar’s image, and he actively takes advantage of this.

The rebel general is so confident of success that he more than once openly ignored the peacekeeping efforts of external forces. Attempts by Russia, the European Union, and, more recently, Turkey to bring the parties to the inter-Libyan conflict to the negotiating table were frustrated due to his irreconcilable position.

So, last year, on the eve of the peace conference on Libya under the auspices of the UN, the general launched an attack on Tripoli. As a result, the negotiations broke down, although the day before the start of the conference, Haftar promised the organization’s Secretary General Antonio Guterres to take part in the meeting.

The general also demonstrated his wayward character during the preparations for the Berlin Conference. Although back in the fall, when the German authorities offered their platform for inter-Libyan consultations, Haftar supported the idea. However, the conciliatory position of the military leader was then justified by the unsuccessful assault on a number of Libyan cities. When the LNA's position strengthened, the attitude towards the negotiations changed again.

Moscow consultations

Haftar’s change of mood directly affected Russian interests. The fact is that the timing of the Berlin Conference was constantly changing. The parties to the conflict put forward new conditions and refused to compromise.

When negotiations in the German capital were finally scheduled for January, the rebel general began storming nearby cities and announced a new offensive on Tripoli. The Berlin meeting was in jeopardy.

Based on the experience of interaction on the inter-Syrian settlement, Moscow and Ankara decided to apply it in Libya. At negotiations in Istanbul, Vladimir Putin and Recep Tayyip Erdogan called on the parties to the conflict to establish a ceasefire from January 12. The West fully supported this initiative.

It was unclear until recently whether Tripoli and Tobruk would listen to the Russian-Turkish peace initiative. But a couple of hours before the recommended date, the confrontation stopped. The next day, Saraj and Haftar were expected at negotiations in Moscow to consolidate the achieved truce on paper. They confirmed that they would come.

Participants in the inter-Libyan negotiations were received in the Russian capital by Sergei Lavrov and his Turkish counterpart Mevlut Cavusoglu. Soon they were joined by the heads of the defense departments of the two countries. The document that Saraj and Haftar were asked to sign was discussed in advance by the mediators with the heads of Egypt and the UAE.

Until recently, all participants in the Moscow consultations were tormented by the question of whether Sarraj and Haftar would agree to meet face to face to sign the document. As a result, when everything was ready for negotiations, the general asked for time to think. It soon became known that he left Moscow without signing anything. He explained his sudden departure by his reluctance to see Turkey among the mediators.

Bet on Berlin

The exact date of the Berlin Conference became known literally a week before. Nevertheless, doubts remained as to whether all participants in the inter-Libyan negotiations would come to the German capital and whether General Haftar would disrupt the discussion again.

At the negotiations between Vladimir Putin and Angela Merkel in Moscow, the Libyan issue was one of the central topics. The German Chancellor did not hide that she was interested in Moscow’s continued support for Germany’s peacekeeping efforts.

“The Berlin conference on Libya is not the end, but the beginning of a political process under the auspices of the UN,” Merkel said, enlisting the support of Russia, Turkey, and a number of other countries interested in resolving the conflict.

Despite Russia's active participation, it was unclear whether Vladimir Putin would come to Berlin.

Haftar's sudden disappearance from the Moscow negotiations was seen by many as disrespect for the host side. But by the evening of January 17, the Russian leader confirmed his participation. At the same time, a letter from Haftar addressed to Putin was published on the Kremlin website.

“I express to you my personal gratitude and appreciation for the efforts of the Russian Federation to establish peace and stability in Libya. I express my full support for the Russian initiative to hold peace negotiations in Moscow, which should lead to peace in Libya,” the address said.

Not an inch of land

The head of the Center for Islamic Studies at the Institute for Innovative Development, Kirill Semenov, believes that the polite tone of Haftar’s letter does not justify his actions in Moscow. The expert believes that the general realized the importance of these negotiations for Russia. But the dialogue still broke down.

“This is not the first time the general has behaved so unpredictably. Last year he disrupted a UN conference by launching an assault on Tripoli. Although he assured everyone that he was ready for a truce. Even if Haftar signs something in Berlin, you cannot completely trust him. He may give in to a momentary impulse and change his mind. In Moscow, I think, they will draw appropriate conclusions and approach dialogue with him carefully,” Semyonov expressed his opinion to RIA Novosti.

Libyan political scientist and journalist Mustafa Feturi considers Haftar’s demarche at the negotiations in Moscow to be quite predictable.

“The general has been trying to take control of Tripoli for almost a year. But it fails. Now, finally, he was able to turn the tide, take Sirte and weaken the resistance in Misrata. But participation in any peace negotiations means concessions and surrender of positions taken. Haftar is not ready for this. If he cedes even an inch of occupied land, his main goal - to take the Libyan capital - will move even further away,” a Libyan expert shared his vision with RIA Novosti.

Semenov believes that sooner or later the general will have to give in.

“Haftar cannot endlessly prepare for the assault on Tripoli. The forces are unequal. After the breakdown of the Moscow negotiations, I do not rule out that he will lose the support that external forces provided him. In addition, Haftar is not the only representative of the government of the eastern territories, but only a military leader. If he tries to disrupt the Berlin Conference again, even his allies will speak harshly to him,” the political scientist concludes.

Source: https://ria.ru/20200119/1563561151.html

How and with what to glue plexiglass at home | Methods

Plexiglas is a transparent material that has a durable structure. It is very popular in everyday life - various products are made from it, used in interior decoration, and used in artistic creation. Just how to glue plexiglass so that it holds firmly and the seam is free of cracks and unevenness? There are many compositions that are perfect for fastening this material, but it is first worth considering their types and application features.

What is plexiglass

Plexiglas is a synthetic polymer made using acrylate resin. But still, this is not glass; in fact, the material is hot-melt transparent plastic.

The material has the following properties:

• Has low density;
• It can be scratched easily;
• Processing is very simple;
• Excellent withstands strong impacts;
• The base allows ultraviolet rays to pass through;
• It is highly resistant to moisture, bacteria, and fungal infections;
• High environmental friendliness;
• Begins to melt at temperatures above 100 degrees.

Plexiglas is often used at home to construct various products. The material is suitable for aquariums, crafts, figurines. In manufacturing, it is used to make contact lenses, lamp equipment, door inserts, store displays, clear structure fencing and other products.

Types of glue for plexiglass

There are several types of plexiglass adhesive, each of which can have a different composition, action, and structure. In stores you can find different adhesive compositions suitable for this material, but you should first study their composition.

There are two groups of glue:

• The first group includes glue, which contains an acrylic filler and a solvent. It works on the principle of cold welding, allowing you to create seams that will be similar in composition to plexiglass. After application, the surface of the two parts being joined melts slightly, as a result they are firmly connected;
• The second group includes products with epoxy resin. They are suitable for filling cracks. After application, it must be left for some time to allow the composition to dry.

All glue found in stores may be based on acrylic filler with a solvent or epoxy resin. You should choose depending on your own wishes, but first you should carefully study the composition.

Popular glue brands

You can glue plexiglass to plexiglass using special adhesives that are designed for this material. The following brands are especially popular:

• "Second". It has a high hardening rate and has a viscous structure. It is used to fill cracks and restore chips;
• Rexant (with dichloroethane). This is a transparent composition for gluing polymer materials. Acts on the surface of plexiglass as a solvent. Not destroyed by exposure to water;
• ACRIFIX 1S 0116. Has strong adhesion to products and does not require pressure. It has a viscous structure and, when used, creates a uniform and durable seam.

If you don’t want to spend money, you can make glue for plexiglass with your own hands. The preparation of the composition is quite simple and requires only a few components - acrylic chips and a solvent. Acrylic is placed in a glass container, filled with solvent and left for a day. After 24 hours, it’s worth checking; if the composition turns out to be very liquid, you can add a little crumb and leave it for another day.

How to glue plexiglass together

To glue plexiglass together, you need to study the important features of this process. You should first prepare the material, wipe it with ethyl alcohol and degrease the surface, this will ensure better adhesion. The product must be clean and smooth.

At home, you can glue plexiglass with dichloroethane or regular acetone. But the latter composition dissolves the structure of the material quite poorly, so its use will not be able to create a strong and wear-resistant seam. It is better to give preference to formulations with dichloroethane.

Standard method

Plexiglas is usually glued using popular adhesives containing acrylic, solvent or epoxy resin. But to get a strong and wear-resistant seam, you need to do everything correctly.

So how to glue plexiglass at home? The following instructions will help with this:

1. The surface is first degreased. A cloth or napkin is moistened with solvent or gasoline, and then the surfaces on which the glue will be applied are wiped well;
2. Next, the elements of the product must be fixed, there must be a gap between them;
3. The adhesive composition is applied to both parts in the form of a uniform layer. To make it convenient to apply the product, you can use a medical syringe. It is better to cut the needle a little so that the composition does not splash;
4. The components are then brought together and pressed tightly until they are completely interlocked. For better fixation, you can install a weight;
5. The product should be kept in a compressed position for 1 to 30 minutes.

Bonding with vinegar

At home, to fix products, you can use an affordable and inexpensive product - vinegar essence. Only a concentrate is suitable for gluing, but even it will not be able to create a strong and transparent seam.

Gluing plexiglass with vinegar is carried out as follows:

• The liquid must be applied to the edges of the product;
• Afterwards the edges are tightly compressed;
• The top layer softens, this is what allows you to create a solid seam;
• The products to be glued should be pressed down with a weight and left for a day.

Vinegar with a strength of 50-70% is suitable for gluing. It allows you to temporarily secure plexiglass products. The seam will not be strong, it will quickly become unusable.



Methods of gluing to different surfaces

Plexiglass can be glued not only to each other, it can be glued to other materials. It is often combined with metal, wood, plastic and ordinary glass. In order for the connection to be strong, it is worth knowing the gluing features in each case.

How to glue plexiglass to metal

Sometimes you need to glue products made of plexiglass and metal, but how to make a strong and continuous connection. To do this, you should use the following adhesive compositions:

• Products based on dichloroethane;
• Glue 88;
• Liquid Nails.

The gluing process is carried out according to standard instructions. The surfaces are degreased, prepared, after they are joined, the composition is applied to them. For good fixation, you can place a weight on top for a while.

How to glue plexiglass to wood

Not many people know how plexiglass works with wood. First of all, it is important to choose the right adhesive material that will clearly match the composition. The strength and uniformity of the seam will depend on this.

The following brands of glue are suitable for gluing products made of plexiglass and wood:

• MAFIX;
• Super glue;
• COSMOFEN.

It is worth doing a test test first to make sure that the products are really suitable for joining different materials. The gluing is carried out according to the general scheme.

How to glue plexiglass to plastic and glass

I would like to note that gluing plexiglass to plastic and glass is quite difficult. Often the seam turns out to be fragile and quickly becomes unusable. Therefore, after gluing, you should not expect that the connection will last a long time.

For gluing, use the following glue:

• COSMOPLAST;
• COSMOFEN;
• COSMOFEN PMMA.

Gluing is carried out in the same way as for products made of plexiglass. It is important to strictly follow all stages; obtaining a uniform seam without cracks and deformations depends on this.

To fix plexiglass products, a variety of adhesive compositions can be used, which can create a uniform and durable seam. Before using them, you should carefully study the composition, structure, appearance and properties. They must be suitable for this particular material, because only they can create a strong connection. And the gluing process itself must be carried out in accordance with the instructions and in compliance with all stages.

Source: https://vseprikleim.ru/raznoe/sposoby-skleivaniya-orgstekla-v-domashnix-usloviyax

Where is gallium found in nature?

Gallium is one of the elements that does not occur as ore deposits. The material is very dispersed in the earth's crust. In nature, it is found in extremely rare minerals such as gallite and zengeite. During laboratory experiments, a small amount of gallium can be isolated from the ores of zinc, aluminum, germanium, and iron. Sometimes it is found in bauxite, coal deposits, and other mineral deposits.

Areas of application

Gallium has not yet found application in industry. This is due to the widespread use of aluminum, which has similar properties in solid form. Despite this, gallium looks like a promising material because it has excellent semiconductor properties.

This metal can potentially be used for the production of transistor elements, high-temperature current rectifiers, and solar panels.

Gallium looks like an excellent solution for making optical mirror coatings that will have the highest reflectivity.

The main obstacle to the use of gallium on an industrial scale remains the high cost of its synthesis from ores and minerals. The price per ton of such metal on the world market is more than $1.2 million.

To date, gallium has found effective use only in the medical field. The metal in liquid form is used to slow down bone loss in people suffering from cancer. It is used to quickly stop bleeding in the presence of extremely deep wounds on the body of victims. In the latter case, blockage of blood vessels by gallium does not lead to the formation of blood clots.

Finally

So we found out what kind of metal melts in the hand. Today, gallium can be found on sale for conducting your own experiments. However, the material should be handled with extreme caution. Solid gallium is a non-toxic substance. However, prolonged contact with the material in liquid form can lead to the most unforeseen health consequences, including respiratory arrest, paralysis of the limbs and a person entering a coma.

Source: https://monateka.com/article/179571/

What metal melts in your hand?

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Question for experts: what is the name of the metal that melts in the hand?

Best regards, Natalya =)

Best answers

There are such low-melting metals, and there are three of them. Firstly, it is the well-known mercury, cooled below -39°C (at this temperature it freezes). Such mercury, of course, will quickly melt in a warm hand, but you need to be careful not to frostbite your own hand.

The second such metal is silvery-white, very soft - cesium, which melts at 26.4 ° C. But conducting an experiment with it is much more dangerous than with mercury, since here you can, on the contrary, severely burn your hand: cesium oxidizes so quickly in air that it ignites.

Finally, the third fusible metal is gallium. Gallium melts at 30°C, and therefore your hands should not be particularly cold during the experiment.

The metal that melts in the hand is gallium.

You can’t melt the sodium in your hand, and the potassium too. But gallium and mercury can be

There are such low-melting metals, and there are three of them. Firstly, this is the well-known mercury, cooled below -39°C (at this temperature it freezes). Such mercury, of course, will quickly melt in a warm hand, but you need to be careful not to frostbite your own hand.

The second such metal is silvery-white, very soft - cesium, which melts at 26.4 ° C. But conducting an experiment with it is much more dangerous than with mercury, since here you can, on the contrary, severely burn your hand: cesium oxidizes so quickly in air that it ignites.

Finally, the third low-melting metal is gallium, deposits of which were found in 1932 in our USSR (in Siberia - in Western Altai). Gallium melts at 30°C, and therefore your hands should not be particularly cold during the experiment.

answer

This video will help you figure it out

Answers from experts

Gallium: 29.76 °C
low toxicity, you can pick it up and melt it!

Cesium - 28.44 °C,
but you can’t take it in your hands, only an ampoule with it. The activity of cesium is so high that it spontaneously ignites in air and explodes on contact with water.

This is the well-known mercury, cooled below -39C (at this temperature it freezes). Such mercury, of course, will quickly melt in a warm hand, but you need to be careful not to frostbite your own hand.

The second such metal is silvery-white, very soft - cesium, which melts at 26.4C. But conducting an experiment with it is much more dangerous than with mercury, since here you can, on the contrary, severely burn your hand: cesium oxidizes so quickly in air that it ignites.

The third low-melting metal is gallium, deposits of which were found in 1932 in Siberia (Western Altai). Gallium melts at 30C, and therefore your hands should not be particularly cold during the experiment.

Gallium begins to melt at the temperature of the human body. You hold it in your hands and it begins to turn into liquid, put it out of your hands and it hardens again

All the answers are correct, but it is strongly not recommended to take potassium, sodium and even calcium into your hands

sodium, probably. Rose alloy is also low-temperature in terms of melting

mmm.. alkali and alkaline earth metals well.. maybe something else.
These include elements of groups 1 and 2 of the periodic table

maybe sodium?
If you try really hard.

Alkali metals: potassium, sodium

Wood's alloy, indium alloys, mercury.

Rubidium t melt 38.5 deg. WITH; cesium 28.4; mercury -38.83

Guys, do you even look in reference books when you write answers?
Lithium melts at +180, sodium at +98, potassium at -+65. What hot hands you have to have for the potassium to melt in them! Of the alkali metals, only rubidium has a more or less comparable melting point - +38.9. So if anyone has a fever, rubidium will melt.

And so - only gallium (+29.8).
And indium-gallium eutectic finally melts at +11. By the way, gallium is one of the few substances (along with water and cast iron) for which the density of the solid phase is lower than that of the liquid: gallium “ice” floats in liquid gallium.

Wood's alloy, by the way, melts at +65. So it will melt in hot tea (which Wood himself joked about with his guests), but not in his hands.

And mercury is generally a liquid metal!

It should be noted that mercury is a “liquid” metal under normal conditions

gallium, indium, mercury - melt, sodium, potassium - cut with a knife

Source: https://dom-voprosov.ru/prochee/kakoj-metall-plavitsya-v-ruke

⚡ Spot welding machine from an old microwave oven

If you think that only a magician can pull a rabbit out of a hat, you are mistaken. With some skill, anyone can do this. And the ability to transform one object into another is also magic that can be learned.

The main thing is to find a suitable and very experienced mentor. This could be the author of the NRV Wood channel for you. A very inventive master constantly pleases his subscribers with interesting products.

A striking example is the welding machine he made from a microwave oven.

Why you shouldn't throw away your old microwaves

Any modern electrical device is a masterpiece of engineering and the fruit of the labor of many people. In the era of consumerism, all this is of little value, and in the pursuit of new products, people simply throw even functional devices into the trash and rarely bother with the question of whether they can be used in some other way. And it’s completely in vain, because such a decision will help not only save your money, but also enrich your home with interesting and useful things.

In this case, too, the microwave was replaced by a more modern model. And instead of sending this device to rust in a landfill, the master decided to use the spare parts for a good cause

What can be used from a microwave for a new design?

The microwave needs to be disassembled. It's not difficult: the case can be easily removed, revealing all the complex electronic contents. Don’t rush to throw anything away, today you will need a few parts, but the rest will also be useful for other purposes

The spare part you need is a two-turn transformer, which is located in this microwave oven. It must be removed from the housing. The capacitor must be disconnected from the transformer. You may find it useful for many other inventions, but not in this case. So don’t rush to get rid of it either. Another part from the microwave that you will need is a wire for connection.

There is no point in looking for something else. This one is already grounded and made quite well. In addition, it connects perfectly to the transformer.

But remember: do not touch the transformer connected in this way with your hands, you can receive a powerful discharge that can cause irreparable harm to your body

Thus, you only need two parts from the microwave: an electrical cord with a plug and a transformer.

How to assemble a welding machine from a microwave

A standard microwave oven transformer has two windings: primary and secondary. The secondary one is made of thin copper wire, which is not required for the welding machine.

The secondary must be removed, but this must be done very carefully so as not to damage the primary winding. The author first cut off the outer parts of the secondary with a grinder. After cutting, copper remained inside the transformer, which also needs to be removed from the housing. To remove it, you need to drill holes and knock out the remaining wire with a chisel.

In principle, the entire procedure can be done without a grinder and a drill, using only a chisel and a hammer. The place of the secondary winding will be taken by a power cable for welding machines. It should be quite flexible to fit easily into place.

Another important requirement for this part is reliable winding. The most successful option is a KG cable with one core consisting of many copper wires and a thick rubber sheath. Tinned end switches must be installed on the cable. Subsequently, you can use copper electrodes for welding if you prepare a comfortable handle for them. All that remains is to connect the transformer to the power supply and try it in action.

The author conducted an experiment on an ordinary nail. As you can see, the metal melts at the point of contact with the end switches. The welding machine is ready. It will definitely come in handy for various plumbing jobs. It will help heat up metal in a confined space, for example, to remove a nut. The thicker the cable you use, the more powerful the result.

If you add a convenient handle with an electrode to the design, you can use it for spot welding and soldering with brass or copper

And this example is not all that can be used from an old microwave. But you must admit, the idea is quite interesting and visual, especially since the design is primitively simple and can be assembled in literally an hour.

Here is another interesting example of using a microwave oven for other purposes. In it, the author demonstrates a working model of a spot welding unit, which is based on the same transformer:

What do you think about the author's idea? How realistic is it to make such a welding machine with your own hands? Perhaps you have already tried to assemble something similar? Write about it in the comments!

PHOTO: -channel “NRV Wood”

And if you have your own developments, and you did not forget to photograph the process of their creation, then send a photo with a description to our editors, we will be happy to publish your master class!

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Source: https://homius.ru/apparat-dlja-tochechnoj-svarki-iz-staroj-mikrovolnovki.html

Melting metal at home

For a long time, men began to think about how to create their own furnace for melting metal at home. It must be portable and meet all conditions. The production facility has furnaces for melting large quantities of metal. At home, you can assemble a furnace for melting up to five kilograms of aluminum. Let's look at how to make a smelter at home.

Melting metal at home

Equipment and materials you will need

In order to melt metal, you need to buy the following components for manufacturing:

• fire brick;
• nails;
• transformer;
• copper wire;
• graphite;
• mica;
• asbestos and cement tiles;
• gas-burner;
• crucible.

The dimensions will vary depending on the wishes of the person collecting it. It is better to create a small furnace for melting metals if you want to use it only for your needs. You will spend less time making it, and a small amount of kilowatts will be spent heating it. If you do it using diesel fuel or coal, then do not forget about installing thermal insulation and air supply.

Homemade crucibles

Metals such as iron, nickel, tin, and copper are melted in an electric furnace. The output voltage in an electric furnace should be greater, which means the distance between the electrodes will increase. Brushes from an electric motor are suitable instead of electrodes.

How to make a melting furnace at home - read the following instructions:

• A high-frequency alternating current generator is installed.
• Spiral winding. Made from copper wire.
• Crucible.

All these elements are placed in one housing. The melting cup is placed in the inductor. The winding is connected to the power source. When the current is turned on, an electromagnetic field appears. The resulting eddy currents pass through the metal in the cup and heat it. Melting occurs.

Homemade muffle furnace

The positive properties of an induction furnace are that when melting metals, a homogeneous melt is obtained, alloying components do not evaporate, and melting occurs quite quickly. In addition, the installation of such a stove does not harm the ecosystem and is safe for the user.

Cooling can be done using a fan. Only the latter should be located as far as possible from the furnace, otherwise its winding will serve as an additional closure of the vortex flows. This will reduce the melting quality.

Wheel furnace

Features of melting some metals

In order to melt metal at home, this element must be placed in a small cup or crucible. The cup with the material is inserted into the oven. Then its melting begins. To melt the precious elements, they are placed in a glass ampoule. In order to make an alloy from several components, follow these instructions:

• First, a refractory element - copper or iron - is placed in the melting cup.
• Then a more fusible component is placed - tin, aluminum.

Melting aluminum in a homemade furnace

Steel is a refractory material. Its melting point is one thousand four hundred degrees Celsius. Therefore, to melt steel at home, you must follow the following instructions:

• To melt steel at home, introduce additional regenerators. If the furnace runs on electricity, then electricity is used.
• During induction heating, slags are added. They increase the speed of melting.
• Constantly monitor instrument readings. If necessary, lower the melting temperature by switching to a more moderate mode.
• It is always correct to determine whether the steel is ready for work or melting. Follow all the above steps. Only then will the resulting metal be of high quality.

Metal smelting

To melt iron at home, the furnace must be preheated. First, a large piece is placed, and then small ones. Iron must be turned over in time. A properly molten metal will have a spherical shape.

If you are going to make bronze, you must first place copper in the melting hole. Since this component is more refractory. When the copper is melted, tin is added.

Under no circumstances should elements such as cadmium, lead or zinc be melted. When burned, they produce toxic yellowish smoke.

And when melting aluminum, tin or iron, you must be careful. Rivet slowly and should be done with a small hammer. Heat the material frequently until reddened and cool in cold water. Only then will you get the perfect alloy at the end.

Source: https://stankiexpert.ru/spravochnik/materialovedenie/plavka-metalla-v-domashnikh-usloviyakh.html

An interesting fact from the history of the development of chemistry. Chemistry - interesting facts

In the 21st century, chemistry, along with mathematics and physics, has penetrated into all spheres of people's lives. Medicines, mirrors, car tires Chemical elements surround us everywhere. Even a person himself consists of molecules and chemical chains. We present interesting facts about chemistry.

The amazing is nearby

1. The process of transition of a substance from a solid to a gaseous state in chemistry is called sublimation.
2. To make kvass, a fermentation reaction is used.
3. If you put cheesecloth and rice into over-salted soup, the dish can be saved, since the salt will be drawn out due to absorption.
4. Feces contain skatole, which is what makes them smell bad.

   Interestingly, skatole smells pleasant in small quantities and is added to cigarettes and perfumes.

5. 100,000 - this is how many chemical reactions take place in a second in the human brain.
6. Lego plastic contains barium sulfate. This substance is completely harmless to the human body.
7. September 16 is the International Day for the Preservation of the Chemical Element Ozone.

8. The sulfur it contains causes tears in a person when cutting onions.
9. Interesting facts about chemical elements. Many elements are named after countries - Americium, Indium, in honor of cities - Ytterbium, Berkelium, Holmium, in honor of scientists - Boron, Mendelevium.
10. Dephlogisticated air is the scientific name for oxygen.
11. American Charles Goodyear accidentally discovered the vulcanization process and created durable rubber that does not soften in the heat and does not crack in the cold. He simply forgot a mixture of sulfur and synthetic rubber on a hot stove.
12. When washing clothes, hydrolysis of salts occurs.

Interesting facts about substances. Unusual facts about chemical elements

Some sciences are accessible only to a select few. This is not secret knowledge, you just need to have the appropriate mindset. This is why physicists or chemists look like aliens among office staff or philologists. In general, a deep immersion in some science isolates the researcher from the surrounding world. But in any scientific discipline there is a lot of interesting things. For example, chemical elements.

Hydrogen

Liquid hydrogen (hydrogen) is considered the densest substance (liquid), and in gaseous form it is the most tenuous. The Earth's crust contains only 0.15% of this element, while the Sun consists of about 50% of it. By the way, the most common compound on the planet is dihydrogen monoxide.

Gold

This precious metal is found almost everywhere. As much as 7 mg can be collected in a ton of ocean water. Even in the human body, in theory, there is about a few tenths of a milligram. This is tragic news for those seeking to enrich themselves, but it saves millions of lives.

Silver

We are accustomed to the fact that this is the “second” most valuable precious metal. Fans of jewelry are traditionally divided into fans of gold or silver. But the bactericidal properties of silver products were discovered by accident in the army of Alexander the Great.

During one of the campaigns, an epidemic of intestinal diseases began among the soldiers. At the same time, the authorities remained healthy, and they drank the same water, because the commanders really cared about their soldiers. The answer was in the container from which they ate.

Ordinary soldiers ate from tin plates and therefore became ill, but silver dishes neutralized bacteria in food and water.

Liquid metals

There are four metals that are liquid at "room temperature". That is, they do not need to be specially heated for them to shimmer quietly. These are mercury, gallium, francium and cesium.

Platinum

Immediately after the isolation of this metal, it was called “silver.” It is too similar to ordinary silver and cost several times less. Apparently our ancestors were so accustomed to processing silver that they did not highly value its “analog”. The price of platinum soared when its applications opened up (for example, electronics or medicine).

Pure iron can also be in a gaseous state. It will only need to be heated to 50,000 degrees Celsius.

Interesting facts on chemistry for the wall newspaper. Interesting facts about chemistry

We live in a time when chemistry as a science has become omnipotent and has penetrated into all spheres of human life. Therefore, it could not help but arouse the deepest interest among ordinary people who have nothing to do with science.

We will present interesting facts about chemistry that are understandable to everyone. One of the relevant and useful questions concerns methyl alcohol.

This substance is almost impossible to distinguish from ethyl alcohol, but the effects of the former are very harmful to human health and its use can be fatal.

A very small dose of methanol can deprive a person of his vision, and drinking more than 30 ml of alcohol leads to death.

Now it becomes clear why people get poisoned when they drink low-quality alcohol. And the most amazing thing is that there is an antidote and it is ethyl alcohol.

Source: https://interesnyefakty.com/novosti/interesnyy-fakt-iz-istorii-razvitiya-himii-himiya-interesnye-fakty

What is the name of the metal that melts in your hand?

Gallium is a metal that melts in the hand. The substance has a melting point of 29.76 o C. If you place it in a warm palm, it gradually begins to transform from a solid state to a liquid form.

How was gallium discovered?

The existence of gallium was predicted by D.I. Mendeleev in 1871 on the basis of the Periodic Law formulated by him. Mendeleev gave this element the name “eka-aluminium” and predicted its properties such as density and melting point. Mendeleev also predicted:

• character of the oxide,
• connection in compounds with chlorine.
• that the metal will slowly dissolve in acids and alkalis;
• it will not react with air;
• eka-aluminum oxide M₂O₃ must react with acids to form salts MX₃;
• that it must form basic salts;
• chloride is more volatile than ZnCl₂;
• that this element will be discovered using spectroscopy.

Mendeleev turned out to be Nostardamus in chemistry: when gallium was obtained, all the properties predicted by the scientist were confirmed!

In 1875, French chemist Paul Émile Lecoq de Boisbaudran studied sphalerite using spectroscopy and discovered two purple lines belonging to the new element. A year later, the scientist isolated a new element using electrolysis.

Boisbaudran named this element after the Latin name of France - Gallia. There is a legend that the scientist put another meaning into this name. Lecoq is consonant with the French le coq, i.e. "rooster" (in Latin gallus).

Boisbaudran, as if inadvertently, immortalized his name in the name of the new element.

Read also: Electrode consumption rate for 1 pipe joint

By studying the resulting gallium, Boisbaudran determined that the density differed from that predicted by Mendeleev. When Mendeleev found out about this, he wrote to his French colleague with a recommendation to double-check the results. And as it turned out, it was not in vain: Boisbaudran’s first data were indeed incorrect.

Applications of gallium

Most of the gallium mined is used to produce semiconductors. Arsenide (GaAs) and gallium nitride (GaN) are used in electronic components of many devices, to create integrated circuits, high-performance processors, and microwave amplifiers.

Gallium arsenide is used in various electro-optical infrared devices. Gallium-aluminum arsenide is used to create high-power infrared laser diodes. Blue and violet laser diodes are produced based on gallium nitride and indium gallium nitride.

By the way, gallium nitride laser is used in Blu-ray disc drives.

Solar cells based on gallium arsenide, phosphide and indium gallium arsenide are installed on space satellites and rovers.

Gallium has an interesting feature: it greatly lowers the melting point of the alloys in which it is contained. In this case, the temperature drops lower than that of each component of the alloy separately (eutectic compositions). Thus, the Galinstan alloy (68.5% gallium, 21.5% indium and 10% tin) has a melting point of -19 °C and is used in some thermometers instead of mercury.

Gallium is also used in medicine. In general, the metal is characterized by low toxicity and does not perform a natural biological function. Therefore, gallium-based drugs can be used in the treatment and diagnosis of cancer (gallium-67 and -68 isotopes). Gallium is also used in the treatment of certain bacterial infections: the Ga³⁺ ion replaces Fe³⁺ in the metabolic pathways of bacterial respiration, causing their death. Gallium-based drugs can be used in the treatment of malaria.

Gallium also helps detect neutrino particles emanating from the Sun. As a rule, identifying such particles is a very complex and time-consuming process. Gallium in the registration mixture increases the sensitivity of the analysis and, accordingly, helps to detect neutrinos.

The GALLEX detectors of the Gran Sasso National Laboratory contain 12.2 tons of gallium-71. They capture neutrinos emanating from the Sun and turn it into a radioactive isotope, the radiation of which can be recorded.

Similar studies are also carried out at the Baksan Neutrino Observatory (Kabardino-Balkaria), where neutrino detectors contain 5 tons of liquid gallium.

You can check thermometers by the melting temperature of gallium! This value - 302.9146 K (29.7646 °C) - is recognized as a standard by the International Bureau of Weights and Measures.

In 2007, using 7 nm thick gallium ion beams, Simon Fraser University printed the world's smallest book, Teeny Ted from Turnip Town. The book turned out to be 0.07 x 0.10 mm in size.

Read also: How to drill glass

Gallium has another fun use: gallium spoons, which look indistinguishable from aluminum, are used for the vanishing spoon trick. In hot tea or coffee, such a spoon will simply melt!

Gallium is a chemical element from group 3 of the periodic table of Mendeleev. It has an atomic number of 31, an atomic mass of 69.72, is symbolized as Ga, and has a silvery-white soft metallic color.

Gallium is mined only mainly from zinc ores and bauxite; it does not exist in its pure form.

But what is surprising for the average person is that having a very low temperature for melting, you can see with your own eyes, not in laboratory conditions, how the metal literally melts in your hands, like snow. Gallium melts at 29.8°C.

Who can use this? Maybe many. Despite its melting, gallium is widely used in microelectronics, and low-melting alloys have been created using this metal since 1875, when it was first discovered.

Currently, a chemical called gallium called gallium arsenide (GaAs) is used in infrared applications and microwave circuits.

But in modern lasers, various LEDs of blue and ultraviolet light, another metal compound is used - gallium nitride.

It is widely used in medicine, since it has been found that gallium particles can replace iron particles necessary for the functioning of the body. It is also included in various medications. In addition, quartz thermometers for measuring high temperatures are filled with gallium metal, replacing the mercury we are used to. This is due to the fact that, compared to mercury, the metal has a very high boiling point.

For humans, direct contact with metal is harmful. Acute poisoning can be identified by the following signs: short-term arousal, areflexia, lethargy, adynamia, impaired coordination of movements, slowdown and irregular breathing rhythm. And in parallel with all this, paralysis of the lower extremities occurs, and as a result - coma and death.

It is also considered a very expensive metal on the world market. For example, according to 2005 data, one ton of metal cost 1.2 million US dollars. Of course, scientific progress does not stand still, and the most widespread issue now is the extraction of gallium when creating liquid fuel from coal.

Source: https://morflot.su/kak-nazyvaetsja-metall-kotoryj-plavitsja-v-ruke/