Answer:
d.) belong to the same family of elements
Explanation:
All atoms of elements present in same group having same number of valance electrons. Thus the elements in same group having same properties.
For example:
Consider the second group. It consist of alkaline earth metals. There are six elements in second group. Beryllium, magnesium, calcium, strontium, barium and radium.
All have two valance electrons.
Electronic configuration of Beryllium:
Be = [He] 2s²
Electronic configuration of magnesium.
Mg = [Ne] 3s²
Electronic configuration of calcium.
Ca = [Ar] 4s²
Electronic configuration of strontium.
Sr = [Kr] 5s²
Electronic configuration of barium.
Ba = [Xe] 6s²
Electronic configuration of radium.
Ra = [ Rn] 7s²
