00:01
There, to answer this question about what are valence electrons, we need to think about our model for an atom.
00:13
In our model for the atom, we of course have a nucleus, and in that nucleus we find protons and neutrons.
00:30
All right, and then around that nucleus is where we find the electrons.
00:34
Electrons are found in energy levels, and each energy level can hold a specific number of electrons.
00:50
The first energy level, which we call n equals 1, can hold a maximum of two electrons.
00:59
Let's change color here for that.
01:02
All right, so n equals 1 can hold a maximum of two electrons.
01:07
The next energy level out is simply called n equals 2.
01:11
Very creative here.
01:12
It holds a maximum number of electrons of eight.
01:24
The next energy level, n equals 3, can hold a maximum of 18 electrons, and we can go on from there.
01:33
But the point is electrons are found in their energy levels.
01:40
So valence electrons are those electrons in an atom located in the highest energy levels.
02:00
For example, let's say we have maybe a sodium atom...