Question

How many electrons in an atom could have these sets of quantum numbers?

n=2 --> number electrons = ?

Answer 1

The n=2 shell can hold a total of 8 electrons, with 2 in the 2s subshell and 6 in the 2p subshell.

Step-by-step explanation:

The student has asked about the number of electrons that can occupy the n=2 shell of an atom. Starting with the 2s subshell, which has a quantum number l of 0, there are two possible states for the magnetic quantum number (m), which can only be 0 in this case, and two possible spins (+1/2 or -1/2) for each electron. Thus, there are 2 electrons possible for the 2s subshell. For the 2p subshell, with quantum number l of 1, there are three possible values for m (-1, 0, +1) and two spins for each, resulting in 6 possible states. Therefore, the n=2 shell can contain a total of 8 electrons.