The pair of electrons involved in a covalent bond is called a(n) electron pair, whereas the electrons not involved in bonding are called an unshared or pair.

it's c. elements are placed in rows based on how may valencies electrons have.

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each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.