Physical properties

The category of physical properties is one of the mostbroad synthetic concepts, which characterizes a vast range of properties of substances, objects and phenomena, without which the cognitive activity of man is simply unthinkable.

In the broadest sense, these properties characterize all the non-chemical properties of substances, that is, those that are inherent in matter outside of its interaction with other substances.

These include properties such as metricsmelting and boiling points, heat capacity and thermal conductivity, density of matter. Electrophysical properties include inductance, thermal conductivity and dielectric permittivity. Very important are such properties as absorption, color, concentration.

The most important condition for understanding the essence of physicalproperties and that region of characteristics that they reflect is played by the fact that the substance can be chemically neutral and stable only in the case when the structure and composition of its molecules are stable. This is important because, even when in the same aggregate state, the physical properties of the substance may be different. These differences are predetermined by various circumstances, for example, the structure of the crystal lattice, its presence in the composition of a solution, and others.

All without exception substances in naturehave physical properties, which determine its role and place in natural processes. For example, the melting point (quite often this property is cited in the handbooks as the setting temperature), this is the temperature boundary at which a solid crystalline body can go into a liquid state. In this definition, it is important to understand that the word "can" is the key word, that is, it means that at a given temperature, the substance can be in a liquid state or in a solid state. But, if this temperature is slightly increased, then the substance will undoubtedly become liquid, and, accordingly, vice versa. This physical characteristic of a substance is closely related to another property - the boiling point, but these properties become identical only when it comes to pure matter.

If we consider such physical properties aselectrical conductivity, electrical conductivity, belonging to a subgroup of electrophysical, it should be said that these properties characterize the ability of a human body to pass an electric current through itself. Depending on this, those bodies that conduct electric current are called conductors, and those that do not pass through are called dielectrics. Based on their data physical characteristics, we can immediately conclude about the chemical properties. Conductors always have free carriers of electric charge, but dielectrics may not. This statement allows us to conclude that physical properties are closely related to chemical properties, and they mutually determine each other.

With the help of physical parameters it is possible to describea huge amount of substances and objects that surround us in nature. For example, the basic physical properties of nitrogen - the substance, which is the main component of the air we breathe, are as follows.

Nitrogen is a colorless gas that hasthe melting point is -210 ° C, and at a temperature of -196 ° C, nitrogen boils. Nitrogen is soluble in water, and its density is 0.0012506 g / cm3. The permittivity of nitrogen is 1,000,528 at a temperature of 25 ° C.

Or, for example, the physical properties of ozone,are characterized by such indicators. Ozone is also a colorless gas, with a specific smell and taste, in the liquid state it acquires a dark blue hue, and in the solid becomes black. The melting point of ozone is -192.7 degrees, and it boils at -111.9 ° C. Ozone is soluble in water, has a permittivity of 1.0019 (at 0 ° C), and its density is 0.002144 g / cm3 (at 20 ° C).