Question

Which pattern on the periodic table is correctly predicted below?

Groups determine the number of valance electrons and periods determine the number of energy levels
Groups determine the number of energy levels and periods determine the number of valence electrons
Groups determine the number of protons, and periods determine energy levels
Groups determine the number of neutrons, and periods determine valence
Plzz

Answer 1

A.
Groups determine the number of valance electrons and periods determine the number of energy levels.