How Covalent Bonds Form

hi my name is David Bunn and I'm going

to do a quick tutorial video today on

covalent bonding so for this video we're

going to use the carbon atom and we're

going to use the hydrogen atom and these

are these atoms show how atoms can share

electrons very well so that's why we

chose those now a quick back up in case

you're not sure of what these

illustrations represent this here this

is the nucleus of an atom and it has the

protons and neutrons in it this

particular atom is carbon carbon is

number six on the periodic table which

just means that it has six protons

inside the nucleus so that blue circle

is a nucleus the the yellow circles here

as I put down here in the corner are

electrons they have a negative charge

and you can see for every positive

charge so there's six positive charges

here we have six negative charges which

basically neutralizes this atom it makes

it a neutral atom you'll have you'll

have six pluses and six minuses which is

going to equal out to a no charge and

you'll notice that there are circles

around the nucleus here these are are


energy levels or orbitals and what they

do is they give the electrons a place to

spin just like my pen is spinning around

here right now that's what the electrons

do kind of like planets around the Sun

they orbit and they they stay for the

most part in this particular energy

level and each energy level has a

certain maximum number of electrons you

can put in it so this first level holds

two and then the second level it has

four in it but it can actually hold

eight it the second level holds eight

electrons and that's atoms don't

necessarily like that they don't

necessarily like to have empty energy

levels or even almost full in if we

talked about ionic bonds you might know

that sodium is it has one extra electron

and chlorine has it's one short and

filling that up and so they tend to get

rid of or add electrons well carbon in

this case isn't going to want to stay

like this either so what happens is is

that it will try to find a way to

fill up that second shell and now since

it has four it's not gonna just dump on

and become an ion in which you may have

learned about if we learned about ionic

bonding what its gonna do it's gonna try

and find a way to fill this up without

getting rid of electrons or trying to

just grab on to free electrons floating

around so what happens with a covalent

bond covalent is is basically a sharing

bond and what will do is it will go

around and it will try to find other

atoms that need help filling their

energy levels hydrogen is a great

example hydrogen's a very reactive atom

because it has only one electron here in

this shell and so what it'll do is if

they get close enough they'll actually

come together here and then they'll

share their electrons so it'll kind of

spin around like this and so what

happens is for a little while this

hydrogen will will have both of these

electrons spinning around and that will

give it to in that first orbital or

energy level so that makes it equal or

I'm sorry makes it full and then over

here carbon will take this electron

every once in a while and that will give

it to there now this hydrogen he's happy

but carbon not yet because it still has

to fill these other empty spots so right

now this outer energy level for carbon

it has its four that were originally

there Plus this one so it has five

there's still room for three more and so

this right here this is called a

covalent bond and that's a pretty strong

bond and holds pretty tight but again

not happy so what we'll do is we'll

bring this other hydrogen here this

hydrogen we're gonna kind of run out of

space here but let's see let's move

everything over just enough here to to

get this taken care of

so we'll bring this hydrogen up here

spin him around for effect bring it

here and then this hydrogen also can

come up here and bond there so again

let's let's get this mess here taking

care of a little bit too tight now again

this all these are going to bond and

they're going to share I guess it's kind

of the example would be is if you is you

and a couple buddies wanted to go in for

a TV and you couldn't afford the TV

individually but if you pull your money

together then you can buy the TV the

problem is though is that you have to

share so that's what's going on here

these these electrons are being shared

between the carbon and the hydrogen and

now what's happening is everybody well

all these atoms are happy so there's two

for this hydrogen two for this hydrogen

two Fitness hydrogen 2 for this hydrogen

and that fills its first level the first

level can only hold to carbon it has to

in the first and then it has 1 2 3 4 5 6

7 8 in the second so now it's happy as

well now what you'll find in a lot of

these cases where you have a covalent

bond sometimes they don't share equally

water is an example of that where the H

the two H's and the O and h2o they're

not shared equally but it still solves

the problem it's it's a best-case

scenario for this and so we've done is

we've formed a compound and it's a

covalently bonded compound and how we

would write that we would write the

carbon atom and then we'd write the age

and we put a subscript 4 here and that's

ch4 which is methane gas another way you

can draw this is with the carbon and we

use this stick model the stick shows a

covalent bond and this is a little

faster way to show what's going on

without drawing all the electrons so

there's C and then the four H's and each

of these sticks represents a covalent

bond so that's it's a pretty complex

process but just for the for the basic

idea of how this works this is a

covalently bonded CH 4 compound