## Number of electrons

Raashi Chaudhari 3B
Posts: 64
Joined: Wed Sep 30, 2020 9:31 pm

### Number of electrons

How do we determine how many electrons are in certain quantum numbers?
For example how do you know how many electrons there are when n=3?
I understand that the l value tells the shape, but what does the the n and ml value represent and how do you know how to get those corresponding numbers?

annabelchen2a
Posts: 73
Joined: Wed Sep 30, 2020 10:01 pm

### Re: Number of electrons

n is the 1st quantum number - it represents the energy level of the electron.

When n=3, you know there's 3s, 3p, and 3d - 3s holds 2 electrons max, 3p holds 6 electrons max, and 3d can hold 10 electrons max. In total, this energy level can hold 2 + 6 + 10 = 18 electrons.

the ml value is the 3rd quantum number (the magnetic quantum number), which can have the value of anywhere from -l to l. It specifies a specific orbital amongst a particular set.

Vivian Hoang 1H
Posts: 69
Joined: Wed Sep 30, 2020 10:09 pm

### Re: Number of electrons

Raashi Chaudhari 2D wrote:How do we determine how many electrons are in certain quantum numbers?
For example how do you know how many electrons there are when n=3?
I understand that the l value tells the shape, but what does the the n and ml value represent and how do you know how to get those corresponding numbers?

Hey! You can also get the amount of electrons in each energy level (n) by the formula $2n^2$. So, for 3, it will be 18 electrons max.

Juwon Lim 2A
Posts: 71
Joined: Wed Sep 30, 2020 9:49 pm

### Re: Number of electrons

There are a max of 2 electrons per orbital. So if n = 3, there can be 3s, 3p, 3d Orbitals. There is 1 type of s-Orbitals, 3 types of p-Orbitals, and 5 types of d-Orbitals. Therefore, if each orbital can have 2 electrons max, we can have (3s) + (3p) + (3d) = (2) + (6) + (10) = 18 electrons total for n = 3.