Basic Atomic Structure: A Look Inside the Atom

let's take a closer

look

atom

s are the building blocks that make up everything all stuff everywhere here I've got some drawings this is table salt a solid here's water a liquid and finally oxygen gas and what we're

look

ing at here is what we'd see if we could take these three things and zoom in zillions and zillions and zillions of times and if we could

look

at these closely enough we'd be able to see the

atom

s these little building blocks that make everything up now

atom

s aren't really little colored circles but it's a good way to think about them and it's the way we'll usually draw them when we're learning about this stuff

atom

s are super tiny they are so tiny it can be really hard to wrap your head around how tiny they are here is something that might help you think about this take a piece of paper

look

at how wide it is here all right this is so incredibly thin now

atom

s are so small that it would take 1 million

atom

s lined up next to each other in a row to be as thick as this tiny width of paper that's how small

atom

s are now what I want to do now is

look

even closer at now let's take one of these

atom

s here and zoom in even more so we can see what's inside of it here's a magnified view of one

atom

it's not a perfect representation of exactly what an

atom

would

look

like but it's close enough for right now and check this out the

atom

itself is made up of even smaller things right so that we said...

abs are like the building block for all of stuff but then if you

look

at an

atom

it has even smaller building blocks that make it up so in the center of the

atom

is something called the nucleus and the nucleus is made up of two tiny particles there are protons which I've drawn as red circles here and then they're neutrons which I've drawn as blue circles nucleus is here in the middle of the

atom

and then on the outside of the

atom

there are these little black circles that I'm using to to represent electrons the electrons you'll see are connected to these sort of oval paths and I've drawn these in to show that the electrons are constantly moving they're flying around the outside of the

atom

at an incredibly high speed whereas the nucleus stays solid here right in the middle of the

atom

now electric charge is very important when we're talking about

atom

s for a number of reasons protons have a positive charge a proton has a charge of 1 plus electrons on the other hand have a negative charge one electron has a charge of 1 minus now neutrons they don't have an electric charge at all of charge of 0 and neutral is a word that we use to refer to something that doesn't have a charge so neutrons sounds a lot like neutral now positive and negative charges attract remember that opposite charges attract and that has important consequences for how this

atom

works we said that these electrons are flying around the outside of the

atom

they're...

moving really fast so why don't they just fly out into space well the reason why is because the negatively charged electrons are attracted to the positively charged protons so the protons kind of pull the electrons in they keep them from just flying away but the electrons are moving around so fast that they're not able to actually pull in here and actually touch the protons so that's why they keep staying on the outside and don't just crash in here and all touch the protons now sometimes people ask well neutrons neutrons don't have a charge why are they important at all well it seems that neutrons help keep all of the particles in the nucleus strongly connected to each other now electrical charge is important something else that's important with

atom

s is what their masses how much they weigh so in order to figure that out we have to

look

at the mass of the various things that make up the

atom

now a proton and a neutron are very very similar in size and in mass and they both weigh about this many grams

look

at what a tiny number this is right there's a decimal place all the way over here this is a number that it's best to represent in scientific notation instead but however you write this it's a really tiny unwieldy number so scientists came up with another way to to measure the mass of a proton or neutron and that's using a unit called the AMU the

atom

ic mass unit and they said okay one proton or one Neutron weighs about 1 amu...

that's a lot easier to use than this measurement here so proton or neutron weighs about 1 amu an electron on the other hand is much much much smaller than a proton or neutron it weighs only 0.0005 for naught amu so a tiny fraction of how much our proton or a neutron weighs for this reason when we're talking about the mass of

atom

s which we'll talk about later on we usually add up the protons and neutrons to find out how many am use um the

atom

weighs and then we usually don't even worry about the electrons at all because they're just they're so tiny they don't really have much of an influence on how much an

atom

weighs it's like when you get on a scale to weigh yourself you don't worry about the ring you're wearing or whether you're wearing a necklace or something because those things are just so tiny they weigh so little compared to how much you weigh that it doesn't really influence your weight so protons and neutrons 1 amu and electrons a tiny fraction of that now I send to the

atom

the way it's drawn here isn't a perfect representation of what

atom

s would actually

look

like we'll talk more about that later but there are two things that I want to yup for right now the first is the electrons and how they move this drawing might make you think that the electrons are spinning around in Nice circles on the outside of the

atom

that's actually not what happens they're buzzing around much more randomly kind of...

like hyperactive flies all over the place we'll talk more about that later the second thing has to do with the size of the nucleus and how far the electrons are from it if this were a real

atom

blown up many many times and the nucleus were the size of a grape the electrons out here would be almost a mile away so have this grape sized nucleus and a mile away would be the electron spinning on the outside so that means that most of an