Good morning John in this video I kind of want to give you half a semester of college level chemistry and I only have four minutes to do it so I'm going to get started.

Everything in the world is made up of ATOMS. Atoms are very small. Atoms have protons and neutrons in their nucleus and electrons orbiting those protons and neutrons. The number of protons in an atom tells you what kind of atom it is, by which I mean what sort of element that is. Protons are positively charged and electrons are negatively charged. By definition atoms have no charge so if they have fourteen protons they have fourteen electrons. If they have a different number of protons and electrons then they are an ion not an atom. The number of neutrons in an atom can vary, not just element by element but individual atom by atom of the same element.

That's enough about protons and neutrons; let's talk about electrons. Electrons orbit the nucleus of an atom in specific orbitals. And electron orbitals really like to be full. Orbitals come in four basic flavors: S, P, D, and F. S orbitals contain two electrons, P orbitals can contain up to six, D's ten, and F's fourteen. Orbitals fill in the following order: S, then S, then P, then S, then P, then D, then S, then P, then D, then F.

So if you have one electron, in your atom, if you are hydrogen for example, then you have one electron in your first S orbital. If you are carbon, then you have six, so you have two electrons in your first S orbital, two electrons in your second S orbital and then two electrons in your first P orbital. That is denoted as shown below: 1S² 2S² 2P². Two-pee-two-pee-too.

So basically carbon is four electrons away from being happy. Because if electron orbitals aren't full, they're a little bit like Bella without Edward. So how can Bella fill her Edward shaped hole? I mean how can carbon get those extra four electrons? Carbon does that pretty much invariably by linking with two other atoms. Carbon will then basically share its electrons with other atoms, while those other atoms are sharing its electrons with carbon. And if it shares with hydrogen you end up with things like methane, or if it shares with oxygen you end up with things like carbon dioxide. Oddly enough those are the two principle greenhouse gases. Bella Swan, why must you fill your orbitals!?

These kinds of bonds, in which atoms overcome their initial repulsion in order to share electrons and make their orbitals happy are called covalent bonds. Covalent bonds are not the only type of bonds. Sodium, for example, only needs to lose one electron in order for its orbitals to be happy. Chlorine on the other hand, only needs to get one electron in order for its orbitals to be happy. So what happens when chlorine and sodium see each other is instead of sharing an electron, sodium actually gives its electron to chlorine permanently but then they are so close together that because this is now negatively charged and this is positively charged they stick together. And they make salt!

When atoms or molecules make or break new covalent or ionic bonds their properties drastically change. Sodium on its own, for example, explodes when you put it in water and chlorine... obviously chlorine gas is extremely deadly. But then when you bond them together ionically, they become delicious on food! Physical changes, like melting or freezing or breaking or vaporizing do not change the fundamental properties of the atom or molecule. It's the chemical changes that are really fascinating, and that's what chemistry is about.

If we could talk more about chemistry John, we would talk more in depth about chemical reactions, what kinds of chemical reactions there are, and why atoms and molecules like to react in different ways. Unfortunately we don't have time for that so you're just going to have to deal with having as much knowledge about chemistry as you have now, which is infinitely more than you had four minutes ago. John, I will see you on Monday.

A quick note: there are three messages that I would like to bring you in this video that do not have anything to do with chemistry.

One: Shawn Ahmed, who is a kick-ass nerdfighter who has been doing amazing work in Bangladesh, is one of the five finalists who was picked to possibly go to the world economic forum in Davos. Shawn will be representing the cause of global poverty, the amazing power of YouTube, and of course, Nerdfighteria. It would be great if everyone would follow the link in the sidebar and go vote for him.

Two: obviously the situation in Haiti is dire and we all need to help in whatever way we can. One really easy way to help is to text Haiti to 90999. This will charge an extra 10 dollars to your cell phone bill which will be donated 100% to the Red Cross mission to help Haiti. If you want to give more than 10 dollars, which I hope you do, there is a link to the Red Cross in the sidebar.

Three: If after you're done with those things you still have some more time, my favorite fictional YouTube show, Robot Ninja and Gay Guy, has been nominated for a Streamy award and you can go and vote for that in the sidebar as well.

That's all, Thank you, hope you learned something, Bye.