Question

question 5 1 pts i can determine the number of valence electrons in an atom of a representative element (s and p blocks) by _______________. looking at their group/family number. looking at their atomic mass. looking at their atomic number. looking at their period number.

Explanation:

For representative elements in the s - and p - blocks, the number of valence electrons is equal to the group/family number (with some minor adjustments for groups 13 - 18 where the number of valence electrons is group number - 10 for groups 13 - 18). Atomic mass, atomic number, and period number do not directly give the number of valence electrons for this purpose.

Answer:

looking at their group/family number.