The columns on the Periodic Table are called because they all have similar properties.

The elements in a all have the same number of electron shells.
Group 1 is known as the electron.
Group 2 is known as the electrons. which all have 2 valence
Group 17/7A are known as the electron from other elements. , and like to "grab" an extra
Group 18/8A are the elements. which do not react with other
Valence electrons are the electrons the electron shell on an atom.
which all have 1 valence
or

1 answer

are responsible for the chemical properties of an atom.