The energy shell associated with lowest energy is :

The correct option is A

K

The explanation for the correct answer

Option A

The energy shell associated with the lowest energy is the K shell.

• The electrons in an atom are arranged in shells that surround the nucleus, with each successive shell being farther from the nucleus.
• These shells are represented by the letter K, L, M, N, and so on.
• a Maximum number of electrons that can be accommodated to a particular shell is given by $2{\mathrm{n}}^2$ where n is the number of shells.
• The first shell is represented by the letter K (n=1).
• The K shell has the least energy.
• It can accommodate a maximum of 2 electrons.

The explanation for the correct answers

Option B

• The second shell is represented by the letter L(n=2).
• This shell has energy greater than the K shell.
• It can accommodate a maximum of 8 electrons.

Option C

• The Third shell is represented by the letter M(n=3).
• This shell has energy greater than the L shell.
• It can accommodate a maximum of 18 electrons.

Option D

• The fourth shell is represented by the letter N(n=4).
• This shell has energy greater than the M shell.
• It can accommodate a maximum of 32 electrons.

Conclusion: Hence Option A is correct.