Distinguish the technological, physical, mechanical and chemical properties of metals. Physical ones include specific gravity, color, electrical conductivity. The characteristics of this group also include thermal conductivity, fusibility and density of the metal.
The mechanical characteristics include plasticity, elasticity, hardness, strength, viscosity.
Chemical properties of metals include corrosion resistance, solubility and oxidizability.
Such characteristics as "fluidity", hardenability, weldability, ductility, are technological.
Physical properties
- Color. Metals do not pass light through themselves, that is, they are opaque. In reflected light, each element has its own hue - color. Among technical metals, only copper and its alloys are colored. For the remaining elements, a shade from silver-white to steel-gray is characteristic.
- Fusibility. This characteristic indicates the ability of an element to change into a liquid state from a solid under the influence of temperature. Melting is considered the most important property of metals. In the process of heating, all metals from a solid state pass into a liquid. When cooling the molten substance, a reverse transition occurs - from liquid to solid.
- Electrical conductivity. This characteristic indicates the ability of electrons to carry electricity by free electrons. The electrical conductivity of metallic bodies is thousands of times greater than non-metallic ones. With increasing temperature, the conductivity index of electricity decreases, and with decreasing temperature, respectively, increases. It should be noted that the conductivity of the alloys will always be lower than any metal constituting the alloy.
- Magnetic properties. To explicitly magnetic (ferromagnetic) elements include only cobalt, nickel, iron, as well as a number of their alloys. However, in the process of heating to a certain temperature, these substances lose their magnetism. Separate iron alloys at room temperature are not ferromagnetic.
- Thermal conductivity. This characteristic indicates the ability of the transition of heat to less warmed from a warmer body without visible movement of its constituent particles. A high level of thermal conductivity allows you to evenly and quickly heat and cool metals. Among the technical elements, copper has the highest rate.
Metals in chemistry occupy a separate place. The presence of appropriate characteristics allows the use of a substance in a certain area.
Chemical properties of metals
- Corrosion Resistance Corrosion is the destruction of a substance as a result of an electrochemical or chemical relationship with the environment. The most common example is rusting iron. Corrosion resistance is one of the most important natural characteristics of a number of metals. In this regard, such substances as silver, gold, platinum were called noble. Nickel and other non-ferrous metals have high corrosion resistance . Ferrous metals are subject to destruction faster and stronger than non-ferrous.
- Oxidation. This characteristic indicates the ability of an element to react with O2 under the influence of oxidizing agents.
- Solubility. Metals with a liquid state of unlimited solubility during solidification can form solid solutions. In these solutions, atoms from one component are embedded in the crystal lattice of another component only within certain limits.
It should be noted that the physical and chemical properties of metals are one of the main characteristics of these elements.