Why is bromine smaller than calcium?

Bromine is element 35, occupying the 4th period (row) and 17th group (column) of the periodic table, with an atomic mass of ~80. Calcium is element 20, occupying the 4th period and 2nd group, with an atomic mass of ~40. read more

Best Answer: a bromine atom is smaller than a bromide ion because a bromide ion accepts electrons from an electron donor making it a negative ion. more electrons = bigger structure. read more

These protons in the nucleus pull on all of bromine's electrons with more strength than the nucleus of potassium, and the stronger pull offsets any size gained by adding electrons. In short, bromine's nucleus pulls harder. When looking at potassium and bromine, it would seem that with more electrons occupying more orbitals, bromine would be larger. read more

a bromine atom is smaller than a bromide ion because a bromide ion accepts electrons from an electron donor making it a negative ion. more electrons = bigger structure. read more