Which effect on atomic size is more significant, the nuclear charge or the energy level that electrons are filling?

Are the equal? They both shrink or enlarge the atom.

Atomic size (Atomic radius) is determined mostly by the electrons, though there isn't really a definite size to an atom... that is, they don't have like... edges, because the electrons are always in motion.

The nucleus is measured in units that are apparently 100,000 times smaller than how the whole atom is measured, which I didn't know until just now when I read this
Atomic radius - Wikipedia, the free encyclopedia

:)