All atoms are electrically
neutral and therefore have the same number of positive and negative
Each electron has a negative electrical charge so there are as many
electrons in an atom as positive electrical charges in its nucleus.
As a result:
- If the number of positive charges in a nucleus is known, then the
number of elecrons around this nucleus is known too.
- If the number of electrons in an atom is known, then the number of
positive charges in the nucleus is known too.
- If a compound has an electric charge ( positive or negative ) then
this compound is not an atom (it is an ion).