Question

what is shielding effect.
....
class 11th Chemistry question give exact answer
...
don't give guessing answers please

Answer 1

The shielding effect can be defined as a reduction in the effective nuclear charge on the electron cloud, due to a difference in the attraction forces of the electrons in the nucleus. It is also referred to as the screening effect (or) atomic shielding.

In a multi electron atom, the electrons of the valence shell(outermost shell) are attracted towards the nucleus and also these electrons are repelled by the electrons present in the inner shells.

On account of this, the actual force of attraction between the nucleus and the valency electrons is somewhat decreased by the repulsive forces acting in opposite direction.

This decrease in the force of attraction exerted by the nucleus on the valency electrons due to the presence of electrons in the inner shells, is called screening effect or shielding effect.

The magnitude of the screening effect depends upon the number of inner electrons ,i.e., higher the number of inner electrons, greater shall be the value of the screening effect.

Answer 2

Answer:

decrease in effective nuclear charge on last shell pf valence electron due to attraction of middle shell electron