15 points for only two question : )
how does electron shielding affect atomic size as you move down a group?
and
explain why noble gases have high ionization energy?

Ionization energy increases as you move left to right in a period . that's why noble gases have high ionization energies.
shielding effect increases from top to bottom in a group atomic size also increases from top to bottom in a group

The answer is yes b ffgnbsfgnbnfgbnfgsnb