Each simple substance, according to its physical properties, is divided into metals and non-metals. How to distinguish metals from non-metals? Some of them are easily identifiable visually: hydrogen is a non-metal, and iron is a metal. But, in order to avoid a possible error in the classification, it is better to define most of the elements by their features.

How to distinguish metal from non-metal?

• All metals, if they are in normal temperature conditions, are solids. The exception to this rule is mercury. All metals are characterized by a metallic luster, they are good heat and electrical conductors. Almost all metals are ductile when physically affected.

• Non-metals are much more different than metals. So, they can be liquid (bromine), solid (sulfur), or gaseous (hydrogen). They are also poor heat and electrical conductors.

• Metals and non-metals have different structures. Non-metals are characterized by a large number of free atoms at the outer level compared to metals. The latter is characterized by a non-molecular structure - a crystal lattice.

• Non-metals have a high redox potential and electronegativity.

• How to distinguish metal from non-metal without studying their physical and chemical properties? To do this, you can use the periodic table: you should mentally draw a line from boron to astatine. The left side of the bottom table shows metals. They can also be found in side subgroups located at the top of the ladder. The remaining parts of the main subgroups contain non-metals.

• In addition, many tables are colored. Non-metals are shown in red in such tables, and metals in green and black.

• Do not forget about the existence of amphoteric elements, which in various chemical reactions exhibit the properties of metals or non-metals. In the periodic table, they are highlighted by shading. They are called semi-metals. Such substances have a metallic luster and are weak electrical conductors.

Metal alloys

In addition, there are also metal alloys in the industry, which were obtained by alloying metal with non-metals or other metals, for example, cast iron, steel, bronze, brass.

Alloys can be made from two or more components. However, not all components interact well with each other, so it is not always possible to obtain the desired alloy. So, for example, iron and lead, lead and zinc do not fuse together, since they do not form a solution in the liquid state.

A prerequisite for obtaining alloys is the formation of a liquid homogeneous solution. The resulting alloys have properties that differ from those of the components from which they were formed.

Pure metals are used extremely rarely in industry, since they do not always have the required properties and economy.

There is another way to distinguish metals from non-metals: a magnet. However, it should be noted that the magnet is a limited tool in the determination of metals, since only non-precious metals have properties of attraction to it. So, for example, cast iron, steel, iron will be attracted to a magnet, but aluminum, silver, copper will not be attracted. In the same way, you will not be able to check gold at home for authenticity.

How to distinguish slag from metal?

Slags are by-products that are obtained as a result of the following processes:

• Melting of non-ferrous and ferrous metals.

• Combustion of solid fuels.

• Electrothermal sublimation of phosphorus.

Metallurgical slags are melts that coat liquid metal in a metallurgical process. After solidification, the slags are stone-like or vitreous substances.

The mineral and chemical composition of slags depends on the following factors:

• Composition of waste ore.

• Fuel.

• Type of metal being smelted.

• Features of metallurgical processes.

• Fuel combustion conditions.

• Slag cooling conditions.

Slag is characterized by its physical properties:

• Melting point.

• Temperature range of solidification.

• Heat capacity.

• Viscosity.

• Ability to dissolve sulfides, oxides, etc.

• Certain density.

• Certain gas permeability.

The optimum melting point of the slag is 1100-1200 ° C. If the steel melts at a temperature of 1400-1500 ° C, then the slag should have a low viscosity, high mobility and fluidity - these conditions ensure the correct formation of the weld in welding. How the molten slag solidifies is very important. Slags do not have a strictly defined temperature melting regime. If the temperature rises, the slag becomes less viscous, and if it decreases, the viscosity increases.

The composition and properties of slags depend on the original fluxes. The submerged metal temperature should be at least 1500-1550 ° C, while the slag temperature should be 1750 ° C.

The question often arises of how to distinguish slag from metal. The main differences are:

Metal is more liquid and mobile.

When melted, you can see how the metal boils, which is not the case with slags.

Slags are more viscous and have a darker color compared to metal.

Slags are always lighter than metals.