Question 03743

Jun 29, 2017

$6$ electrons per energy level starting with the second energy level.

Explanation:

The angular momentum quantum number, $l$, describes the energy subshell in which an electron is located inside an atom.

In your case, $l = 1$ describes the $p$ subshell.

Now, in order to figure out the number of electrons that can have $l = 1$, i.e. the number of electrons that can occupy a $p$ subshell, you must first determine the number of orbitals that are present in this subshell.

The number of orbitals present in a given subshell can be calculated by using

$\text{no. of orbitals} = 2 l + 1$

$\text{no. of orbitals} = 2 \cdot 1 + 1 = 3$

This means that a $p$ subshell, regardless of the energy level on which it is located (for energy levels that are $> 1$, of course), can hold $3$ orbitals.

According to Pauli's Exclusion Principle, each orbital can hold a maximum of $2$ electrons, one having spin-up and one having spin-down.

You can thus say that a $p$ subshell can hold a maximum of

3 color(red)(cancel(color(black)("orbitals"))) * "2 e"^(-)/(1color(red)(cancel(color(black)("orbital")))) = "6 e"^(-)#

Therefore, you can say that $6$ electrons can share $l = 1$ per energy level.