K-shell is the ________ energy level.

Correct option is B

The correct answer is (b) First.
· The K-shell refers to the first energy level or electron shell of an atom, which is closest to the nucleus. It can hold up to 2 electrons.
Information Booster:
· The electron shells are designated in alphabetical order starting with K, followed by L, M, N, etc.
· The K-shell (first energy level) has the lowest energy compared to higher shells like L, M, and so on.
Additional Information:
· Fourth: The fourth energy level is designated as the N-shell.
· Third: The third energy level is the M-shell.
· Second: The second energy level is the L-shell.