The atom charge, along with its quantum numbers, is one of the most important numerical characteristics of atom. Knowledge of a charge of atom is necessary for the solution of various problems of an electrostatics, electrodynamics, atomic and nuclear physics.
It is required to you
- Knowledge of structure of atom, atomic number
1. Atom of any substance consists of an electron shell and a kernel. The kernel consists of two types of particles - neutrons and protons. Neutrons have no electric charge, that is electric charge of neutrons is not equal to zero. Protons are positively charged particles and have the electric charge equal +1. The quantity of protons characterizes atomic number of this atom. The electron shell of a kernel consists of electronic orbitals on which the different quantity of electrons is located. An electron - a negatively charged elementary particle. Its electric charge is equal to-1.
2. To define an atom charge, it is necessary to know its structure - quantity of protons in a kernel and quantity of electrons in an electron shell. The total charge of atom turns out as a result of algebraic summation of charges of the protons and electrons entering it. As a rule, atom is electroneutral, that is the quantity of protons is equal in it to quantity of electrons. The charge of such atom, obviously, is equal to zero. The example - atom of hydrogen H consists of one proton and one electron. Q = 1+(-1) = 0 - a charge of electroneutral hydrogen.
3. Owing to some reasons the quantity of protons and electrons in atom can not coincide. In this case atom is positively or a negatively charged ion. For example, the positive ion of sodium has 11 protons and 10 electrons. Its charge Q = 11+(-10) = 1.