Aatomituumad

Aatomituumad, also known as atomic units, are a system of natural units which are used as a system of measurement in atomic physics and theoretical chemistry. This system is based on the atomic properties of electrons and protons, and it is designed to simplify calculations in these fields by normalizing certain physical constants to 1. The primary atomic units include the atomic unit of charge, the atomic unit of mass, and the atomic unit of length, among others.

The atomic unit of charge, often denoted as 'e', is the elementary charge of an electron, approximately equal to 1.602176634 × 10^-19 coulombs. The atomic unit of mass, denoted as 'm_e', is the rest mass of an electron, approximately 9.1093837015 × 10^-31 kilograms. The atomic unit of length, denoted as 'a_0', is the Bohr radius, approximately 5.29177210903 × 10^-11 meters, which is the most probable distance between the nucleus and the electron in a hydrogen atom in its ground state.

These units are particularly useful in quantum mechanics and other areas of physics and chemistry where atomic and subatomic processes are studied. By using atomic units, complex equations can be simplified, making them easier to solve and interpret. The system of atomic units is not part of the International System of Units (SI), but it is widely accepted and used in scientific literature.