00:01
Chapter 3, problem 16, says, what are valence electrons? and what is so important about valence electrons? valent electrons are electrons that are located in the outermost energy level.
00:30
These electrons are very important because they're used to determine chemical bonding.
00:35
The valence electrons help determine what atoms can bond with a particular atom based on the ability to share those valence or transfer those valence electrons.
00:48
Vailant electrons can be determined by several ways.
00:52
If we think of an atom of lithium, we know that lithium will have three protons in its nucleus.
01:07
The very first energy level of lithium is going to have two electrons.
01:18
Let's go ahead and put a circle around this nucleus.
01:22
There we go.
01:22
The very first energy level will have two electrons in a neutral atom.
01:26
The next energy level will have one electron given that a neutral atom of lithium will have the same number of protons as number of electrons.
01:37
This outer energy level shows the number of valence electrons for lithium, given that it is one.
01:50
The core electrons are the electrons that are not on the outer energy level.
01:54
In this case, for lithium, it's two.
01:56
If we think of the electron configuration of lithium, we can also figure out the number of valence electrons...