Question

Size of atom progressively becomes smaller when we move from sodium (Na) to chlorine (CI) in the third period of the periodic table?

Answer 1

In a period, the size of an atom decreases from left to right. This is because the nuclear charge, i.e. the atomic number increases from left to right in the same period, thereby bringing the outermost shell closer to the nucleus. Therefore, considering the third period given above, it has been found that sodium is the largest in size, while chlorine is the smallest.