Now that we know the three types of elements
that we have in the periodic table, it becomes
important to be able to name the groups.
And, what exactly is a group?
Now, if we take a look here, we’re going
to say this is 1A, 2A, 3A, 4A, 5A, 6A, 7A,
8A.
These are called your main groups.
Groups go vertical.
We’re going to say that there are 8 main
groups.
These are also called our representative elements,
our main group elements.
Now, down here in the pit, these are also
groups but they’re not A-groups, they’re
B-groups.
These are our B-group elements.
They’re not representative elements.
What they’re called instead is that they’re
called transition metals.
You'll learn later on in the semester, why
are they called transitions metals?
Because a majority of these metals will have
more than one charge, that’s why they’re
called transition metals.
They can transition from one state to another
state in terms of charge.
Later on, in this chapter, we’ll talk about
the charges that these different groups hold,
and why they hold those charges.
Again, groups 1A to 8A are called your main
group metals or your representative metals.
In the pit, we have our group B elements,
which are your transition metals.
These two columns here are also transition
metals—these guys here.
Now, we’re going to say many of these representative
groups also has special names associated with
them.
We’re going to say that group 1A, these
elements are called your alkali metals, alkali
metals.
Hydrogen would be an exception.
Hydrogen is not a metal, so it’s not an
alkali metal.
It’s a non-metal.
We’re going to say that the alkali metals
are highly reactive.
If you took for example, if you had a piece
of sodium metal—pure sodium and you dumped
it into water, what would happen is it will
have a violent explosion with that water.
And, as you go down this group to K or Rb,
if you take those and throw into water, the
reactions will be even more violent, leading
to bigger explosions.
That’s why it’s very hard to get a sample
of these pure group 1A elements.
You can’t just go to any store and get some.
They're under lock and key, very hard to get
to.
Group 2A, they’re called your alkaline earth
metals.
3A and 4A and 5A, we don’t have names for
them.
They don’t have any general names to them.
Group 6A, they’re called your chalcogens.
7A, they’re called your halogens.
8A, they’re called your noble gases or inert
gases.
Inert just means they don’t react with anything,
very unreactive.
Alkaline metals are super reactive, inert
gases are very unreactive.
They’re on opposite ends of the periodic
table for a reason.
Now, we’re going to say that these two columns
here also have names.
We’re going to say that this row here, so
all of this right here, these are called your
lanthanides.
And then this row here, these are called your
actinides.
They’re also transition metals but they
have special names associated with them.
So, we've seen the division of the periodic
table in terms of metals, metalloids, and
non-metals.
We’ve just seen that groups go vertical,
up and down, that’s a group.
Groups 1A to 8A are your representative elements
or main group elements.
The majority of them have a special a name
associated with them.
In the pit, we call those our transition metals
or our group B elements.
