Why do 1 mole of cobalt weigh more than 1 mole of boron?

Answer 1

what you are asking is why cobalt is more dense than boron. You will have to ask a higher power than I. But I will do what I can. atoms are weighed in AMU Atomic Mass units. Atoms are measured in angstroms. so an atomic density is the relation of angstroms the atom fills(volume)to how heavy it is(mass). Oh, and the mole is a very large number of atoms or molecules so that these really small weights and sizes become tangeable a.k.a. cubic inches, ounces, pound, cubic yards. Now why is there a difference in density of these substances... well they have more or less protons, neutrons, and electrons. Not to mention different arrangement of the electrons causes a different size. I hope that helped.

Answer 2

One mole of cobalt contains more atoms than one mole of boron because cobalt has a greater atomic mass. Atomic mass is the weighted average of the masses of an element's isotopes, and cobalt atoms have more protons, neutrons, and electrons than boron atoms, leading to a greater overall mass.