ATOMIC NUMBER, MASS NUMBER, ELECTRON (NOMOR ATOM, NOMOR MASSA, ELEKTRON)

1. Atomic Number and Mass Number

The element is a single substance that can not be broken down into other simpler substances by ordinary chemical means. The element can be transformed into other elements through nuclear reaction (nuclear). Inside the nucleus are protons and neutrons determines the mass of an atom. The number of protons or positive charges contained within the nucleus is shown by the Atomic Number (NA or Z).For a neutral atom the number of positive charge (proton) equals the number of negative charges (electrons).

The number of total protons and neutrons contained in the nucleus is shown by the Mass Number (NM or A).