What is the formula when the halogen from 3rd principal energy level combines with you alkaline earth metal from the 4th energy level?

If it is an isoelectronic series select true, if not select false. o2-, s2-, se2-, te2- na+, k+, rb+, cs+ n3-, p3-, as3-, sb3- ag, cd+, sn3+, sb4+ f-, cl-, br-, i- f-, ne, na+, mg2+ s2-, s, s6+

How many atoms or molecules are there in a mole of a substance?

The semi-conductors on the periodic table are classified as