Question

How does the size of atoms (atomic size) generally vary in going from left to right in a period of the periodic table? Why does it vary this way?

How does the size of the atom change along a period of the periodic table from left to right and why?

Answer 1

The size of the atoms decreases on moving from left to right in a periodic table. This happens because the number of electrons and protons also increases and the nucleus of the atom becomes more positively charged. The nucleus exerts a greater force of attraction on the electrons and pulls them tightly. As the nucleus pulls the outermost electrons towards it, the size of the atom (or the atomic radius) decreases.