A common stereotype is that metal is necessarily something heavy, durable, shiny. Of metals make tools and mechanisms, weapons and jewelry. Metals are used for weather protection and food storage. Even a stereotype penetrated the language - the phrase “take some piece of iron"Has a very specific and capacious meaning.
However, not all metals are solid, durable and heat-resistant. And substances such as sodium, gallium, mercury - find unusual uses.
Today, let's talk about ten metals with the lowest melting points.
10. Tin (231 ° C)
The chemical element occupying the jubilee, fiftieth place in the periodic table has been known to mankind since ancient times. First drops tin (Latin name Stannum) primitive people noticed in their bonfires 4 thousand years before our era. No wonder - because tin melts at a temperature of only 231 ° C. At the same time, the tree is just beginning to char and timidly burn.
After hardening, the “tears” with which the beautiful heavy stone cassiderite wept on fire kept their shape in which they had a chance to freeze. So the first metal household items appeared.
When it was succeeded to melt red copper from green malachite, it turned out that the mixture of copper and tin is much stronger than any of the metals separately. It was then that civilization began to develop rapidly. Weapons, armor, dishes, tools - everything was made of durable and beautiful bronze.
9. Lithium (180 ° C)
This amazing metal was discovered only at the beginning of the 19th century. Lithium (Lithium, element No. 3) is quite fusible - liquid metal with a temperature of only 180 ° C can be stirred even with a wooden spoon.
Lithium has a very low density - twice as light as water! The metal belongs to the group of alkali and is rather active chemically (therefore it could not be opened for so long).
In the modern world, lithium is widely used to create amazing alloys - hard, light and heat resistant.
Not a single modern electronic gadget does without lithium. After all, lithium is a key component of compact and capacious batteries. And also, it is lithium that gives a wonderful scarlet color to fireworks.
8. Indium (157 ° C)
At the end of the 19th century, chemists managed to discover and isolate in pure form the element that occupied cell No. 49 in the periodic table. Indium (Indium) Is a rather heavy (almost like iron) metal, melting at 157 ° C.
This material is amazingly soft and ductile. Only talcum powder is softer than this metal! An incredible property has made indium indispensable in electronics. Thin indium strips deposited on glass conduct electricity well - but are completely transparent. So do already familiar to us flat screens based on "liquid crystals" (LCD).
7. Sodium (97.8 ° C)
Sodium (Natrium, 11th element) can melt even in boiling water - 97.8 ° C. But we would not advise letting even a small piece of sodium fall into water (even ice). Sodium alkali metal is very active chemically and immediately reacts, separating hydrogen from water molecules and turning into a strong alkali.
In this case, a lot of heat is released, which immediately sets fire to the released hydrogen. Explosion and fire! Materials such as sodium are stored in kerosene, which eliminates their contact with water and air moisture.
As a very active element, sodium in one form or another is present around us in huge quantities. Take at least sodium chloride - ordinary table salt.
6. Potassium (63.5 ° C)
A close relative of sodium - potassium. Element No. 19 (Kalium) also reacts violently with water, forming an alkali, and also fusible - 63.5 ° C. But there are almost no edible potassium compounds, and in this it is the exact opposite of sodium. Although in limited quantities, the body still needs (trace element).
In its pure form, potassium has no practical use. But its many compounds since ancient times are known as fertilizers, detergents, important components of many chemical processes.
5. Rubidium (39.31 ° C)
37th element of the table - rubidium (Rubidium) only melts at 39.31 ° C. A piece of rubidium can melt on a saucer like butter. This is a light metal, its density is only slightly higher than the density of water. But rubidium reacts with water no less violently than its close relatives, potassium and sodium.
Rubidium is surprising in its chemical properties. Alkali metal itself very easily enters into a variety of chemical reactions. But at the same time, rubidium salts and its alloys with other metals are good reaction catalysts. That is, they significantly accelerate the process, while completely not diverging on their own. This makes rubidium a valuable material for the chemical industry and radio electronics.
4. Cesium (28.5 ° C)
Very soft silver metal literally melts in the hands. At 28.5 ° C cesium (Cesium) becomes liquid and literally leaks between the fingers. But do not try to conduct such an experience! Of all alkali metals, element No. 55 is the most chemically active (second only to France).
In the open air, cesium instantly oxidizes, forming a bright flame. And when it gets into the water, it just explodes. Cesium manages to set fire even to ice! Moreover, cesium hydroxide formed during the reaction with water eats away glass - and slowly gnaws at vessels of gold and even platinum.
But in electronics, such cesium activity allows you to make very sensitive photocells and watches with truly cosmic accuracy.
3. France (27 ° C)
The element occupying the 89th cell of the periodic table is france (Francium) - very similar to cesium. France melts at 27 ° C, but before that, an incredibly active alkali metal still needs to be preserved.
Not only does France react violently with everything, it’s also very radioactive! In just half an hour from a kilogram, France will remain - well, if a handful - of a variety of strongly emitting fission products.
However, in such quantities, no one has ever seen him. It is not surprising that in nature this element is one of the most rare. And he never found practical application.
2. Gallium (26.79 ° C)
And here is silver metal gallium (Gallium - even before the discovery of the element D.I. Mendeleev left cell No. 31 in the table in advance) is much more common and is often used just for fun. It melts almost like cesium, at 26.79 ° C, but otherwise is very different from its “nervous” brother.
Externally and in mechanical properties, gallium is very similar to aluminum. Lightweight, heat-conducting, in its pure form is quite fragile. The dense oxide film instantly formed in air also protects it from destruction.
In its pure form, gallium is practically not used. But its salts and, especially, low-melting alloys have found wide application in nuclear physics, radio electronics, and measuring equipment.
1. Mercury (-38.87 ° C)
We are all familiar with mercury - even today, in the age of electronics, there is hardly any one person who would not be measured body temperature with a mercury thermometer. But few people think that a very fluid heavy silver liquid is a real metal!
Yes, element number 80, Hydrargyrum, melts in the most severe frost - the crystallization temperature of mercury is almost minus forty degrees (-38.87 ° C).
Humanity has been familiar with mercury since ancient times. Mercury is widely used in engineering, chemistry, and metallurgy. This element is worthy of a separate, rather big story - and today it proudly crowns our rating.