Hey, guys, welcome back.
In this new video, we're going to take a look at ionic compounds.
Just realize in the advent of chemistry, in the beginnings of chemistry, there were common
names that were given to tons of different compounds, morphine, quick lime, what have
you.
But just realize, since the early stages of chemistry, hundreds, if not thousands, of
compounds have been identified.
It became more important to find a systematic way of naming each of these compounds.
Instead of using a common name, chemists all around the world decided to use a new form
of scientific naming structure in order to name these new compounds.
They call this structure nomenclature.
Chemists all around the world used nomenclature.
Our main focus here is just to identify the first type of compound we're going to learn
how to name, ionic compounds.
Remember, fundamentally, an ionic compound is just the connection between a positive
ion, which is called a cation, and a negative ion, which is called an anion.
Usually, this positive ion or cation will be a metal.
We're going to say that the negative ion, which is our anion, will be our nonmetal.
If we take a look here, we're going to say metals will tend to lose electrons because,
remember, if you're going to be a positive ion, you have to be losing you negative electrons,
so they're going to be positively charged ions, which we just said were cations.
Nonmetals, on the other hand, nonmetals tend to gain electrons, so you're gaining negative
electrons and as result, you become negative charged.
These negatively ions we said were anions.
Remember, fundamentally, all ionic compounds are a positive ion connecting with a negative
ion.
Usually, this metal will be positive and the nonmetal will be negative.
An example of us having a cation which is not a metal would be ammonium.
Ammonium is a polyatomic ion.
It's NH4+1.
We could have a negative ion, nitrate ion, which is NO3-.
Since they're opposing charges, they're going to be attracted to one another.
So they would form this compound.
It's not always true that an ionic compound is between a metal and a nonmetal.
You most likely won't see things this complex initially, but just realize eventually you
should be able to recognize this.
An ionic compound, again, is a connection between a positive ion and a negative ion.
Usually, that positive ion will be a metal.
In some cases, it could be ammonium or other positive polyatomic ions.
Now, down here we have a periodic table.
What we're going to do here is we're going to go through the different charges that we
expect based on the groups of each of these elements.
Remember, we already talked about this earlier on, but we're just going back to it again
to refresh your memories.
Remember group 1A elements are plus one.
Group 2A are plus two.
Group 3A are plus three.
We're going to say Group 7A is minus one.
Group 6A minus 2.
Group 3A minus three.
These are the things we already know.
Remember Group 4A is midway, so we don't really say that they're strictly positive or negative
here.
Remember, these are the charges associated with each of these groups.
Our transition metals here in the pit – our transition metals have variable charges, meaning
they have more than one charge.
We're going to learn how to name them based on the type of transition metal we have later
on when it comes to nomenclature.
But remember we said that transition metals tend to have more than one charge except for
these common three.
Remember we said that silver is always plus one, cadmium which is Cd is plus two and zinc
is plus two.
Remember, these guys are transition metals.
But unlike most other transition metals, they only have one charge.
Remember, we also said there's another weird thing that goes on, remember that tin and
lead here, both of them are not transition metals, but they act like it because they
have more than one positive charge.
Both of them could be either plus two or plus four.
Those are the different charge distributions that you need to remember.
They're going to help us in naming a lot of different ionic compounds.
So guys, at this point just remember that ionic compound is the connection between a
cation and an anion.
Just remember the different charge distributions associated with the different groups and associated
with certain types of transition metals.