The atoms on left side are larger than the atoms on the right side of the periodic table because those on the right have more proton's.
Explanation:
As we travel along a period in a periodic table then the atomic radii decreases
This is because as we travel along a period we have that the atomic number of the atoms increases which means the the number of proton's increased
But the electron's add to the same outer shell throughout the period , which means the effective nuclear charge increases which pulls the outer electrons toward's the nucleus and the size decreases.
Therefore the atoms on left side are larger than the atoms on the right side of the periodic table because those on the right have more proton's.
