Introduction to Bonding
Now that we are experts on atoms and the periodic table, we are going to look at how atoms can combine in
different ways. We will start by watching a short video and getting some new terms from it. (Watch
“Physical Science Series – Bonding” up to 6:38)
Chemical Bond: An attractive force that holds atoms together, the result of two nuclei simultaneously being
attracted to the same electrons
Chemical Bonding: the process of atoms combining to form new substances
Valence Electrons: Electrons in the outermost energy level
In the movie, we learned that atoms are stable when they have a full outer energy level, or shell. Atoms
want to be stable and will gain, lose, or share electrons to get a full outer shell.
Let’s look at a few examples to see how this happens. You’ll need to take out your periodic tables to see the
electron configurations of the atoms.
First, let’s look at Lithium.

How many electrons does an atom of lithium have? 3

What is its electron configuration?
2-1
Let’s draw this:

Is it happy that way? No, it does not have a full outer shell

How many electrons fit in the first shell?

How many electrons fit in the second shell? 8

So, what are two ways that Lithium could get a full shell and be happy?
2
Lose 1 electron or gain 7
electrons

Which one of those choices do you think would be easier? Losing 1

Would you rather get happy the easy way or the hard way? The easy way.
Well, Lithium would rather do whatever is easiest too. It will lose 1 electron to make its outer shell full, so it
looks like this:

What is its electron configuration now?
2

Is Lithium still neutral when it loses that electron?

How many electrons does it have now? 2

And how many protons?

So what is the charge on this lithium ion?
No
3
+1
Let’s try Fluorine now.

How many electrons does an atom of fluorine have? 9

What is its electron configuration?
2-7
Let’s draw this:

Is it happy that way? No, it does not have a full outer shell

What is the easiest way it can get happy and have a full outer shell?

What is its electron configuration now?

Is fluorine still neutral when it gains that electron?

How many electrons does it have now? 10

And how many protons?

So what is the charge on this fluorine ion?
2-8
9
-1
No
Gain 1 electron