Why Atomic size decreases left to right in a period in MPT?
The Modern Periodic table is made according to increasing number of their atomic numbers . So if we move from left to right in a period the no of electrons as well as the no of protons goes on increasing . The electrons are added to the same orbit or energylevel but the nuclear charge increases by one in each step due to increase in the number of proton by one in each step. So the inward pull increases and the outer orbital shrinks. As a result the atomic size decreases moving towards right in the modern periodic table.