What element has, 86 electrons, 125 neutrons, and 82 protons?

Plz ! ive been stuck on this forever

Which prefix mean under less or below

We can be sure that a mole of table sugar and a mole of vitamin c are equal in their 1) mass in daltons. 2) mass in grams. 3) number of molecules. 4) number of atoms. 5) volume.