The reason for the small radius of Ga compared to Al is ______

Question:
The reason for the small radius of Ga compared to Al is _______.

(i) poor screening effect of d and f orbitals

(ii) increase in nuclear charge

(iii) presence of higher orbitals

(iv) higher atomic number

Solution:

Option (i) poor screening effect of d and f orbitals and (ii) increase in nuclear charge are the answers.