- Okay. Let's take
a look at our electrons.
Now here's the deal,
electrons are negatively
charged particles,
and I'll write it down
in a second.
But I want you to know
that they are these tiny,
crazy tiny, little particles
that are, like,
zipping around the outside
of the nucleus.
They're, like,
orbiting the nucleus,
and they're negatively charged,
and in my picture here,
they're black.
All right.
Let's go write that all--
whoa, that was magic.
Electrons, they
orbit the nucleus.
Orbit the nucleus.
They're negative.
I often draw them like that.
If you have negatively
charged particles
around the outside
of the nucleus
and positively charged particles
on the inside of the nucleus,
what is possibly true about
the charge of the whole thing?
Well, the fact is that you
can count up--
let's see, let's do it in green.
You can count up your charges
to determine the charge
of the atom as a whole.
Whoa, look at this.
So, my inner green circle--
tell me what the net charge
of the inner green
circle is going to be.
You only have positive
particles.
In this little scenario,
you have three
positive particles.
And what were those called?
Those are your protons.
So you have a net charge of 3+,
positive three.
That makes sense, doesn't it?
Outside, orbiting the nucleus,
you have how many electrons?
You have three electrons.
And electrons are
negatively charged,
so you have a negative
three charge.
And tell me,
the atom as a whole,
what is its charge?
All together,
this atom has no charge.
Now, how could we change
the charge of the atom?
Well, we could change
the number of protons.
What's that going to do?
That actually could
change the charge,
but then we're going
to change the element.
And so let's not ever change
the element unless we're told,
okay, what are you
going to do
to go from one element
to the next element,
and then you can change
the number of protons.
But if you're just trying
to change the charge,
change the number of electrons,
and you can.
The element stays the same.
I believe that an element
that has three protons
in it is going to be,
I think it's lithium.
So this is a lithium atom.
And we could either
add electrons--
and this is legit,
dog pound, you can.
I could +1 electron.
Tell me what's going to happen
if I added one electron
into this mix.
Now what's my charge?
Well, check it out.
Now I have four negative charges
and three positive charges,
so I have a net charge of -1.
And here's the thing,
that's okay.
You can do that, and
now you have an ion.
An ion is a charged atom.
And you charge your atom by
changing the
number of electrons.
In this case,
we now have a lithium,
that's my lithium atom,
with a -1 charge.
You can write it
like that or you could
write it like lithium negative.
And those are two ways
to write--
if I showed you this,
I would say, dude,
tell me about this thing.
Tell me everything
that you can know
about that little
symbol right here.
You'd look on your
periodic chart.
You'd be like, oh lithium.
It has three protons,
because I just told you
it was a lithium atom.
And then you'd say, okay,
if it has three protons
but it has a negative charge,
then it has to have three
electrons
to neutralize the charge
and then one more electron
so that now it
has a negative charge.
That's awesome.
That's easy.
Now you know we have four
electrons in this lithium atom.
This lithium ion
because it's charged.
We could take away an electron,
which is also totally legit.
Let's take that electron away.
And if we take it away,
now we--
well, if we took away
four-- we took away one,
then you're going to be back
to neutral again.
But let's say we
go back to three
and we take away one electron,
now you've got two electrons
and three protons,
which means you
have one extra proton,
which gives you
a positive one charge.
So in that case you'd
have lithium positive.
Now, for all the chemistry buffs
out there
and all the chemistry teachers
out there,
I give a big woof,
woof to it ain't that simple.
There are actually rules
about how many electrons
you can lose and how many
electrons you can gain.
And most of the time,
in fact I probably would
have to say all of the time,
lithium will lose and electron,
it won't gain an electron.
And there are-- like,
have fun in chemistry when you
get to learn all those rules.
That's cool.
I want you to know that if we
change the number of electrons,
we get an ion of the same atom.
Now, who the heck cares?
Why are ions important?
Whoa.
When we start talking
about physiological function
of human bodies,
for example, your
entire nervous system
runs on moving ions,
true story.
Sodium ions and potassium ions,
they move back and forth.
Calcium ions move
all around in your body.
You would not be
a functioning critter
if you did not have moving ions
in your body.
They basically are
like electricity.
So understanding the concept
of an ion is really important
for understanding future,
like, processes in cells
and body parts.
Electrons, so, they make ions.
Awesome.
Electrons are also really
important because they allow--
they are chemical bonds.
What? Not James Bonds,
chemical bonds.
That was a good one,
huh?
Electrons--
when two atoms share electrons
in some labor,
that is a chemical bond.
And remember
that we took atoms--
when we had our
little hierarchical--
seriously?
I did that more
than once on accident?
Our hierarchical organization
of living systems,
remember that we combined atoms
together to get molecules.
You are--
you have very few
independent atoms
rolling around in your body.
Most of you is made up
molecules,
which are atoms
that are combined,
that stick together because they
are literally sharing electrons.
Sometimes--
so, okay, let's write this down.
This is a chemical bond.
We're sharing electrons
between two atoms.
Here is my chemical bond.
This is the chemical bond.
Like, I could draw it like that.
That's usually
how I will draw it,
like a line connecting
two atoms.
Chemical bonds come in flavors.
Of course they do.
Some chemicals,
some atoms, form chemical bonds
and they share electrons evenly,
like these guys.
These guys are sharing equally.
This is not an example
of my children.
This is not Keenan,
and this is not Kai.
They do not share equally.
I encourage them to be
this kind of chemical bond.
It's a covalent bond.
Covalent bonds share
atoms equally.
My children tend to be, sure,
more of the polar-- no,
excuse me, we'll do--
they tend to be more
of the ionic bond,
not ironic, ionic.
Isn't it ionic?
That they--
they do not share at all.
In fact, one atom
in an ionic bond--
one atom steals
the electrons completely.
So if these two atoms were
forming a chemical bond
and atom "A" completely
steals the electrons,
like hogs them
all in to its own nucleus,
atom B is sitting there going,
oh, share your electrons please,
I want some.
Atom B is going to hang out and,
like, keep trying
to get its electrons back.
But atom "A" is like,
right dude, you're out of luck.
That is like my children.
Bad boys.
And that's an example
of an ionic bond.
Ionic bonds are
like bully bonds,
they are not equally sharing.
But, of course,
as is all things scientific,
there's a total spectrum
on this thing.
You can be anywhere
on the spectrum
between fully covalent,
sharing equally
and happily and kindly,
to fully ionic like,
dude, I've done
stole your electrons
and good luck getting them back
or somewhere in the middle.
And if you're somewhere
in the middle,
you tend to be called
a polar covalent bond.
And you could figure it out.
If, for example, "A" is kind
of hogging the electrons,
do you kind of agree
that, oh,
it would kind of be sort
of negative,
because it's hogging
the electrons.
And B would be sort of positive
because it's kind
of losing its electrons,
it's losing its
negative charges.
That would be
a polar covalent bond.
This concept
of polarity is really important
when we start
thinking about water,
and we're going to talk
about water today.
So we will come back
to this concept and make sure
that you understand what I'm
talking about, dogs.
All right.
Let's talk--
before we dive into--
oh wow, water is,
like, two away.
We get to talk
about energy first.
But first we're going
to talk about chemical notation
so that we know
what we're writing about.
