As you move from what to what on the periodic table, the atomic radius of the atoms increase

As you move down vertically the radius increases, and as you move right to left the radius increases. However, since the table is split in three parts (metals, transition, and non-metals), it is more complicated when referring to size going right to left. The metals tend to be bigger and as you move right they become smaller, but when you get to the non-metals they increase in size again and then become smaller. But in general, as you move right and down they become smaller.