Group
There are 18 groups in the periodic table. The elements of same group shared similar chemical properties because they have the same number of valence electrons. The groups in the periodic table are numbered from 1 to 18. 
Group 1 (IA) : Alkali Metals 
The IA family is made up of the alkali metals. In reactions, these elements all tend to lose a single electron. This family contains some important elements, such as sodium (Na) and potassium (K). Both of these elements play an important role in the chemistry of the body and are commonly found in salts.
Group 2 (IIA) : Alkaline Earth Metals 
The IIA family is made up of the alkaline earth metals. All these elements tend to lose two electrons. Calcium (Ca) is an important member of the IIA family (you need calcium for healthy teeth and bones).

1. MATTER