Question

In the lithium atom screening effect of valence shell electron is caused by?

• A. Electrons of K and L shell.
• B. Electrons of K shell.
• C. Two electrons of L shell.
• D. None

Answer 1

The correct option is B Electrons of K shell.

There is repulsion between the valence electrons and the electrons present in the inner shells. Due to this, there is a decrease in the force of attraction between the electrons in the valence shell and the nucleus. This effect is known as the screening effect.

In Lithium, the electrons of K-shell causes the screening effect because K-shell is the inner shell in case of Li.

Hence, option B is correct.