Question

The total number of electrons present in anti-penultimate shell of calcium is

• A. 2
• B. 8
• C. 1
• D. 3

Answer 1

The correct option is B 8

The outermost shell is the valence shell. The shell inner to the valence shell is known as the penultimate shell and the shell inner to the penultimate shell is called the anti-penultimate shell.
The atomic number of calcium is 20 and it has an electronic configuration of 2, 8, 8, 2. Thus, the number of electrons in the anti-penultimate shell is 8.
Hence, the correct answer is option (b).