Question

Use the second member of each group from Group IA, IIA and VIIA to judge that the number of valence electron in an atom of the element is the same as it's group number​

Answer 1

Answer:

Group IA: Lithium (Li)

Lithium is in Group IA and has 1 valence electron, which is the same as its group number.

Group IIA: Beryllium (Be)

Beryllium is in Group IIA and has 2 valence electrons, which is the same as its group number.

Group VIIA: Fluorine (F)

Fluorine is in Group VIIA and has 7 valence electrons, which is the same as its group number.