In the periodic system of D.I. Mendeleev there are 118 elements. Let's talk about one of them, standing in 8th place - about oxygen. So what is this substance? We will get acquainted with the physical and chemical properties of oxygen.
General information
Oxygen (O) is a gas that is colorless and odorless. It was opened in 1772-1774. The name, still relevant, was given to the element by the creator of the first nomenclature of chemical compounds A. L. Lavoisier, who considered oxygen to be an integral part of acids. Hence the name of the gas - Oxygene (sour).
The volume of oxygen in dry air is 20.9%. In the earth's crust in the form of various compounds it contains 47.3%.
In industry, oxygen is obtained by fractional distillation of liquid air or by electrolysis of water. The laboratory uses methods of thermal decomposition of substances rich in this element.
Physical properties
We describe the physical properties of the substance:
- atom number is 8;
- atom mass - 15,9994 a. eat.;
- atom volume - 10.89-10 -3 m 3 / mol;
- atom radius - 0.066 nm;
- electronic configuration - 2s 2 2p 4 ;
- electronegativity - 3.5;
- specific heat of oxygen - 0.920 kJ / (kg * K);
- It consists of three stable isotopes 16 O, 17 O and 18 O.
The isotopes of oxygen and other elements are called the types of atoms of the element in question that have the same atomic numbers but different mass numbers.
The specific heat of oxygen and other elements is called the value, which is a numerical value equal to the amount of heat that must be transferred to the mass of the taken substance in order to change its temperature by one.
Chemical properties
Oxygen is a very active element. It is capable of reacting with almost all elements of the Periodic system (except for inert or noble gases). In this interaction, oxides are formed. This occurs when the elements are directly connected to oxygen or when various oxygen-containing compounds are heated. The resulting oxides are resistant to thermal influences.