We're going to say that metals, metals tend to lose electrons to become positively charged
ions called cations.
We're going to say metals that have only one charge associated with them are referred to
as Type I metals.
So let's take a look.
Remember we talked about this way back, the subdivisions of the periodic table.
Remember we said that there's a staircase right here, and we said that these guys here
are the metalloids.
So those are your metalloids.
And then everyone to the right of them are going to be your nonmetals, including hydrogen
and then everything else on the periodic table is a metal.
Now, we're going to say we have main group metals.
We're going to say that the charge of Group 1A is +1, Group 2A is +2, Group 3A is +3.
Now we're going to ask ourselves, why do these guys have these charges?
Let's think about this for a second.
Here we look at lithium.
Lithium is Li.
Lithium has three electrons.
Why do we know it has three electrons?
Because just say that all the elements on the periodic table are in their neutral forms.
Here, this is the atomic number.
So according to the atomic number, we have three protons.
Since we're assuming everyone is neutral on the periodic table, the number of protons
and a number of electrons must be the same.
So if my atomic number is three and I'm neutral, that must mean I have three protons, but more
importantly, I have three electrons, so lithium has three electrons.
Lithium wants to become just like a noble gas.
It wants to become just like a Group 8A element.
Now lithium has two choices to go.
It can either try to gain seven electrons to become like neon which is very unlikely
or it could just lose one electron and become like helium which has two also.
Remember, you always go the shortest distance to get to a noble gas.
So it's better for lithium and the other Group 1A metals to lose one electron.
Neutral lithium has three protons, which are all positive, and three electrons.
When it loses one of its electrons, it's now going to have two electrons and become perfect
just like helium, but its number of protons have to stay the same, because if you change
a number of protons, you change the identity of the element, so your number of protons
are staying the same.
The only thing that's changing are the number of electrons.
That's how we know lithium gains a +1 charge because we have more positives than we do
negatives.
In the same way, beryllium wants to lose two electrons, to become just like helium.
And boron over here, boron tends to lose electrons as well.
We're going to say it loses +3, so these guys here lose +3 to be become just like the noble
gas.
So we're going to say aluminum, for example, has an atomic number of 13, wants to lose
three electrons to become ten just like neon.
Again, we're going to say metals tend to lose electrons to become cations.
We're going to say that Groups 1A, 2A and 3A have the charges of +1, +2 and +3.
Now, they're all Type I metals because they only have one charge.
Now, we're going to say metals that have more than one charge are referred to as Type II
metals.
These are traditionally are transition metals.
Transition metals tend to have more than one charge.
Remember, we said the transition metals are the guys here in the pit.
These guys tend to have more than one charge.
For example, iron has two charges: +2 or +3.
Chromium does too.
A lot of them have more than one charge.
There are three of them, though, that even though they're transition metals, they have
only one charge.
The three that follow that trend are silver, which is Ag, silver is always +1, cadmium,
which is Cd right next to it, is +2 and zinc, right above it, is +2.
These three guys are transition metals.
We expect them to have more than charge, but they are an exception to that.
These are transition metals but they're Type I transition metals.
They have only one type of charge.
Most of the other transition metals have more than one charge, so we would refer to the
other transition metals as Type II.
Now, we're going to say also that tin here and lead, these two right here, they're both
in Group 4A.
Technically, they're not transition metals, but they act like it.
They have more than one charge associated with them.
We're going to say tin can be either +2 or +4 and lead can be either +2 or +4.
Again, as an Sn and Pb in Group 4A, they're not transition metals, but they act like it.
They have more than one charge.