Question

g
Q4. Explain why the atomic and ionic radii of the
alkaline earth metals are lower as compared to alkali
metals. (1.5)
s-block​

Answer 1

Explanation:

The atoms of alkaline earth metals have a higher nuclear charge due to which the electron cloud is pulled towards the nucleus. This causes a decrease in the atomic and ionic radii of alkaline earth metals.

Answer 2

Solution :

• Atomic radius usually reduces as we go from left to right in a period and increases as we go down the group .

• The alkali metals have only 1 electron in their outer most shell hence the nuclear charge which is the force with which the nucleus attracts the electron towards itself will be less .Hence , the decrease in size of the atom will be negligible .

• If we compare this with the alkali earth metals they have 2 electrons in their outermost orbit hence due to the increase in nucleus charge the electrons in the outermost orbit will be pulled inwards .

• Hence , the atomic radii of the alkali earth metals is less than the alkali metals .