Question

Due to screening effect of electrons in an atom:

• A. IE decreases
• B. IE increases
• C. No change in IE
• D. Attraction of nucleus on the valence electron increases

Answer 1

The correct option is A

IE decreases

The more filled inner shells that an atom has, the more the outer electrons will be shielded from the nucleus' attraction. This is because there are more electrons to repel them. The first ionization energy decreases on going down a group. This is because the electron to be removed from the outer energy level is increasingly distant from the nucleus, as a result of the atoms getting bigger. The attraction of the nucleus for the electron becomes less, and it becomes easier to pull it away. Screening effect decreases the attraction of electrons towards the nucleus. So less force is required to remove an electron.