Atomic number

The atomic number, atomic number, atomic number, and atomic number is the number of protons in the nucleus of a chemical element, and therefore also the number of protons. As a symbol for the atomic number is usually chosen. In an uncharged atom the number of electrons in the atomic shell coincides with the number of protons, the atomic number is equal to the number of electrons in the neutral atom.

Ratio of the elements

The atomic number is equivalent to the name of the chemical element, that is, all atoms with the same atomic number belong to the same element. The atomic number determines the classification of each element in the periodic table and is usually indicated on the bottom left next to the element symbol.

Thus, for example, the carbon atom to six protons:

Associated with neutron and mass number

Atoms with the same atomic number but different numbers of neutrons are called isotopes. They have almost the same behavior ( isotope effect ) in chemical reactions. The number of neutrons of an atomic nucleus can be calculated with knowledge of its atomic number and mass number.

Or resolved by the mass number

Atomic number of anti- atoms

For anti- atoms, such as anti-hydrogen whose nuclei instead of protons contain negatively charged antiprotons, the proton number is counted with a negative sign.