The atomic radius<span> actually decreases as you move from left to right in a period (row) of the </span>periodic<span> table. ... The added protons in the nucleus of an </span>atom<span> will pull the </span>electron<span> cloud more tightly inward and shrink the size of the </span>electron<span> cloud which means you have a smaller </span>atomic radius<span>.</span>
