I need help with this question

The tilt of the earth's axis of rotation is responsible for the a) ocean's tides. b) size of the moon. c) brightness of stars. d) earth’s seasons.

The element that has the greatest electronegativity is

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+