[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.14,0:00:03.00,Default,,0000,0000,0000,,We humans have known for thousands of years,
Dialogue: 0,0:00:03.00,0:00:05.87,Default,,0000,0000,0000,,just looking at our environment around us,
Dialogue: 0,0:00:05.87,0:00:07.21,Default,,0000,0000,0000,,that there're different substances.
Dialogue: 0,0:00:07.21,0:00:10.33,Default,,0000,0000,0000,,These different substances...tend to have different properties.
Dialogue: 0,0:00:10.33,0:00:11.95,Default,,0000,0000,0000,,Not only do they have different properties;
Dialogue: 0,0:00:11.95,0:00:14.74,Default,,0000,0000,0000,,one might reflects light in a certain way, or not reflect light.
Dialogue: 0,0:00:14.74,0:00:17.60,Default,,0000,0000,0000,,Or be a certain color, or be have a certain temperature;
Dialogue: 0,0:00:17.60,0:00:20.46,Default,,0000,0000,0000,,be liquid, or gas or be a solid.
Dialogue: 0,0:00:20.46,0:00:22.11,Default,,0000,0000,0000,,But we also start to observe
Dialogue: 0,0:00:22.11,0:00:24.87,Default,,0000,0000,0000,,how they react with each other in certain circumstances.
Dialogue: 0,0:00:24.87,0:00:27.66,Default,,0000,0000,0000,,and here's pictures of some of these substances.
Dialogue: 0,0:00:27.66,0:00:31.48,Default,,0000,0000,0000,,This right here is carbon, and this is in the...in its graphite form
Dialogue: 0,0:00:31.48,0:00:36.07,Default,,0000,0000,0000,,This right here is lead; this right here is gold
Dialogue: 0,0:00:36.07,0:00:38.72,Default,,0000,0000,0000,,and all of the ones that I've drawn, that I've shown pictures of here,
Dialogue: 0,0:00:38.72,0:00:41.37,Default,,0000,0000,0000,,I got them all from this website right over there
Dialogue: 0,0:00:41.37,0:00:45.45,Default,,0000,0000,0000,,All of these are in their solid form, but we also know that we...
Dialogue: 0,0:00:45.45,0:00:47.40,Default,,0000,0000,0000,,It looks like there's certain types of air in it,
Dialogue: 0,0:00:47.40,0:00:49.34,Default,,0000,0000,0000,,certain types of air particles,
Dialogue: 0,0:00:49.34,0:00:52.21,Default,,0000,0000,0000,,and depending on what type of air particles you're looking at
Dialogue: 0,0:00:52.21,0:00:55.08,Default,,0000,0000,0000,,whether it is carbon, or oxygen, or nitrogen,
Dialogue: 0,0:00:55.08,0:00:57.95,Default,,0000,0000,0000,,that seems to have different types of properties.
Dialogue: 0,0:00:57.95,0:00:59.42,Default,,0000,0000,0000,,Or, there are some other things that can be liquid,
Dialogue: 0,0:00:59.42,0:01:02.08,Default,,0000,0000,0000,,or even if you raise the temperature high enough on these things.
Dialogue: 0,0:01:02.08,0:01:05.02,Default,,0000,0000,0000,,If you raise the temperature high enough on gold or lead,
Dialogue: 0,0:01:05.02,0:01:06.50,Default,,0000,0000,0000,,you could get a liquid.
Dialogue: 0,0:01:06.50,0:01:09.84,Default,,0000,0000,0000,,Or if you kind of -- if you burn this carbon,
Dialogue: 0,0:01:09.84,0:01:12.08,Default,,0000,0000,0000,,you can get it to a gaseous state,
Dialogue: 0,0:01:12.08,0:01:13.35,Default,,0000,0000,0000,,you can release it into the atmosphere,
Dialogue: 0,0:01:13.35,0:01:14.70,Default,,0000,0000,0000,,you can break its structure.
Dialogue: 0,0:01:14.70,0:01:17.27,Default,,0000,0000,0000,,So these are things that we've all kind of
Dialogue: 0,0:01:17.27,0:01:20.58,Default,,0000,0000,0000,,that humanity has observed for thousands of years.
Dialogue: 0,0:01:20.58,0:01:22.45,Default,,0000,0000,0000,,But that leads to a natural question
Dialogue: 0,0:01:22.45,0:01:24.23,Default,,0000,0000,0000,,that used to be a philosophical question,
Dialogue: 0,0:01:24.23,0:01:26.40,Default,,0000,0000,0000,,but now we can answer it a little bit better,
Dialogue: 0,0:01:26.40,0:01:30.90,Default,,0000,0000,0000,,and that question is, if you keep breaking down this carbon
Dialogue: 0,0:01:30.90,0:01:33.52,Default,,0000,0000,0000,,into smaller and smaller chunks,
Dialogue: 0,0:01:33.52,0:01:35.55,Default,,0000,0000,0000,,if there's some smallest chunk,
Dialogue: 0,0:01:35.55,0:01:39.87,Default,,0000,0000,0000,,some smallest unit of this stuff, of this substance
Dialogue: 0,0:01:39.87,0:01:43.17,Default,,0000,0000,0000,,that still has the properties of carbon?
Dialogue: 0,0:01:43.17,0:01:45.26,Default,,0000,0000,0000,,And if you were to somehow break that down even further,
Dialogue: 0,0:01:45.26,0:01:48.39,Default,,0000,0000,0000,,you would lose the properties of the carbon?
Dialogue: 0,0:01:48.39,0:01:50.35,Default,,0000,0000,0000,,And the answer is: there is.
Dialogue: 0,0:01:50.35,0:01:52.20,Default,,0000,0000,0000,,And so just to get our terminology,
Dialogue: 0,0:01:52.20,0:01:56.16,Default,,0000,0000,0000,,we call these different substances, that these pure substances
Dialogue: 0,0:01:56.16,0:01:59.02,Default,,0000,0000,0000,,that have these specific properties at certain temperatures,
Dialogue: 0,0:01:59.02,0:02:01.18,Default,,0000,0000,0000,,and react in certain ways,
Dialogue: 0,0:02:01.18,0:02:05.29,Default,,0000,0000,0000,,we call them elements.
Dialogue: 0,0:02:05.29,0:02:08.73,Default,,0000,0000,0000,,Carbon is an element. Lead is an element. Gold is an element.
Dialogue: 0,0:02:08.73,0:02:10.40,Default,,0000,0000,0000,,You might say that water is an element.
Dialogue: 0,0:02:10.40,0:02:14.22,Default,,0000,0000,0000,,And in history, people have referred to water as an element.
Dialogue: 0,0:02:14.22,0:02:17.89,Default,,0000,0000,0000,,But now we know that water is made up of more basic elements.
Dialogue: 0,0:02:17.89,0:02:20.40,Default,,0000,0000,0000,,It's made of oxygen and of hydrogen.
Dialogue: 0,0:02:20.40,0:02:25.01,Default,,0000,0000,0000,,And all of our elements are listed here
Dialogue: 0,0:02:25.01,0:02:27.76,Default,,0000,0000,0000,,in the periodic table of elements.
Dialogue: 0,0:02:27.76,0:02:29.37,Default,,0000,0000,0000,,C stands for carbon
Dialogue: 0,0:02:29.37,0:02:30.40,Default,,0000,0000,0000,,-- I'm just going through the ones
Dialogue: 0,0:02:30.40,0:02:32.38,Default,,0000,0000,0000,,that are very relevant to humanity --
Dialogue: 0,0:02:32.38,0:02:35.50,Default,,0000,0000,0000,,but over time you'll probably familiarize yourself with all of these.
Dialogue: 0,0:02:35.50,0:02:39.15,Default,,0000,0000,0000,,This is oxygen. This is nitrogen. This is silicon.
Dialogue: 0,0:02:39.15,0:02:42.87,Default,,0000,0000,0000,,This is -- Au is gold. This is lead.
Dialogue: 0,0:02:42.87,0:02:51.100,Default,,0000,0000,0000,,And that most basic unit of any of these elements is the atom.
Dialogue: 0,0:02:51.100,0:02:54.56,Default,,0000,0000,0000,,So if you were to keep digging in
Dialogue: 0,0:02:54.56,0:02:57.08,Default,,0000,0000,0000,,and keep taking smaller and smaller chunks of this.
Dialogue: 0,0:02:57.08,0:02:59.42,Default,,0000,0000,0000,,Eventually you would get to a carbon atom.
Dialogue: 0,0:02:59.42,0:03:00.76,Default,,0000,0000,0000,,Do the same thing over here,
Dialogue: 0,0:03:00.76,0:03:02.54,Default,,0000,0000,0000,,eventually you'd get to a gold atom.
Dialogue: 0,0:03:02.54,0:03:03.99,Default,,0000,0000,0000,,You did the same thing over here,
Dialogue: 0,0:03:03.99,0:03:05.86,Default,,0000,0000,0000,,eventually you'd get some of this little small
Dialogue: 0,0:03:05.86,0:03:07.76,Default,,0000,0000,0000,,-- for a lack of a better word -- particle,
Dialogue: 0,0:03:07.76,0:03:09.18,Default,,0000,0000,0000,,that you'd call a lead atom.
Dialogue: 0,0:03:09.18,0:03:11.24,Default,,0000,0000,0000,,And you wouldn't be able to break that down anymore
Dialogue: 0,0:03:11.24,0:03:13.60,Default,,0000,0000,0000,,and still call that lead,
Dialogue: 0,0:03:13.60,0:03:17.04,Default,,0000,0000,0000,,for it still have the properties of lead.
Dialogue: 0,0:03:17.04,0:03:18.33,Default,,0000,0000,0000,,And just to give you an idea
Dialogue: 0,0:03:18.33,0:03:21.19,Default,,0000,0000,0000,,-- this is really something that I have trouble imagining --
Dialogue: 0,0:03:21.19,0:03:24.04,Default,,0000,0000,0000,,is that atoms are unbelievably small.
Dialogue: 0,0:03:24.04,0:03:25.90,Default,,0000,0000,0000,,Really, unimaginably small.
Dialogue: 0,0:03:25.90,0:03:27.56,Default,,0000,0000,0000,,So for example, carbon.
Dialogue: 0,0:03:27.56,0:03:29.38,Default,,0000,0000,0000,,My hair is also made out of carbon.
Dialogue: 0,0:03:29.38,0:03:31.88,Default,,0000,0000,0000,,In fact most of me is made out of carbon.
Dialogue: 0,0:03:31.88,0:03:35.91,Default,,0000,0000,0000,,In fact most of all living things are made out of carbon.
Dialogue: 0,0:03:35.91,0:03:40.53,Default,,0000,0000,0000,,And so if you took my hair. And so my hair is carbon.
Dialogue: 0,0:03:40.53,0:03:42.23,Default,,0000,0000,0000,,My hair is mostly carbon.
Dialogue: 0,0:03:42.23,0:03:43.99,Default,,0000,0000,0000,,So if you took my hair right over here
Dialogue: 0,0:03:43.99,0:03:45.56,Default,,0000,0000,0000,,-- my hair isn't yellow
Dialogue: 0,0:03:45.56,0:03:46.77,Default,,0000,0000,0000,,but it contrasts nicely with the black.
Dialogue: 0,0:03:46.77,0:03:47.95,Default,,0000,0000,0000,,My hair is black. But if I did that,
Dialogue: 0,0:03:47.95,0:03:49.71,Default,,0000,0000,0000,,you wouldn't be able to see it on the screen.
Dialogue: 0,0:03:49.71,0:03:51.97,Default,,0000,0000,0000,,But if you took my hair here, I would have asked you
Dialogue: 0,0:03:51.97,0:03:55.20,Default,,0000,0000,0000,,how many carbon atoms wide is my hair?
Dialogue: 0,0:03:55.20,0:03:58.47,Default,,0000,0000,0000,,So if you took a cross-section of my hair, not the length,
Dialogue: 0,0:03:58.47,0:04:00.36,Default,,0000,0000,0000,,the width of my hair, and said:
Dialogue: 0,0:04:00.36,0:04:03.26,Default,,0000,0000,0000,,how many carbon atoms wide is that?
Dialogue: 0,0:04:03.26,0:04:07.05,Default,,0000,0000,0000,,And you might guess, oh, Sal already told me, it's very small,
Dialogue: 0,0:04:07.05,0:04:09.15,Default,,0000,0000,0000,,so maybe there's a thousand carbon atoms there,
Dialogue: 0,0:04:09.15,0:04:10.48,Default,,0000,0000,0000,,or ten thousand, or a hundred thousands,
Dialogue: 0,0:04:10.48,0:04:11.79,Default,,0000,0000,0000,,and I would say, no!
Dialogue: 0,0:04:11.79,0:04:14.25,Default,,0000,0000,0000,,There are one million carbon atoms.
Dialogue: 0,0:04:14.25,0:04:17.44,Default,,0000,0000,0000,,Or you could string one million carbon atoms
Dialogue: 0,0:04:17.44,0:04:20.93,Default,,0000,0000,0000,,across the width of the average human hair.
Dialogue: 0,0:04:20.93,0:04:22.58,Default,,0000,0000,0000,,And that's obviously an approximation,
Dialogue: 0,0:04:22.58,0:04:24.03,Default,,0000,0000,0000,,it's not exactly one million,
Dialogue: 0,0:04:24.03,0:04:26.60,Default,,0000,0000,0000,,but that gives you a sense of how small an atom is.
Dialogue: 0,0:04:26.60,0:04:28.44,Default,,0000,0000,0000,,You know, pluck a hair out of your head
Dialogue: 0,0:04:28.44,0:04:30.99,Default,,0000,0000,0000,,and just imagine putting a million things
Dialogue: 0,0:04:30.99,0:04:33.99,Default,,0000,0000,0000,,next to each other across the hair,
Dialogue: 0,0:04:33.99,0:04:37.04,Default,,0000,0000,0000,,not the length of the hair, the width of the hair.
Dialogue: 0,0:04:37.04,0:04:39.18,Default,,0000,0000,0000,,It's even hard to see the width of hair.
Dialogue: 0,0:04:39.18,0:04:40.72,Default,,0000,0000,0000,,And there would be a million carbon atoms
Dialogue: 0,0:04:40.72,0:04:42.98,Default,,0000,0000,0000,,just going along it.
Dialogue: 0,0:04:42.98,0:04:48.09,Default,,0000,0000,0000,,Now it would be pretty cool in and of itself
Dialogue: 0,0:04:48.09,0:04:49.03,Default,,0000,0000,0000,,-- we do know that
Dialogue: 0,0:04:49.03,0:04:51.38,Default,,0000,0000,0000,,there is this most basic building block of carbon,
Dialogue: 0,0:04:51.38,0:04:53.93,Default,,0000,0000,0000,,this most basic building block of any element.
Dialogue: 0,0:04:53.93,0:04:55.95,Default,,0000,0000,0000,,But what's even neater is that
Dialogue: 0,0:04:55.95,0:04:59.07,Default,,0000,0000,0000,,those basic building blocks are related to each other.
Dialogue: 0,0:04:59.07,0:05:02.56,Default,,0000,0000,0000,,A carbon atom is made of even more fundamental particles.
Dialogue: 0,0:05:02.56,0:05:07.47,Default,,0000,0000,0000,,A gold atom is made up of even more fundamental particles.
Dialogue: 0,0:05:07.47,0:05:10.44,Default,,0000,0000,0000,,And they are actually defined by
Dialogue: 0,0:05:10.44,0:05:12.76,Default,,0000,0000,0000,,the arrangement of those fundamental particles.
Dialogue: 0,0:05:12.76,0:05:14.09,Default,,0000,0000,0000,,And if you were to change
Dialogue: 0,0:05:14.09,0:05:15.90,Default,,0000,0000,0000,,the number of fundamental particles you have.
Dialogue: 0,0:05:15.90,0:05:17.84,Default,,0000,0000,0000,,You could change the properties of that element,
Dialogue: 0,0:05:17.84,0:05:18.89,Default,,0000,0000,0000,,how it would react,
Dialogue: 0,0:05:18.89,0:05:22.77,Default,,0000,0000,0000,,or you could even change the element itself.
Dialogue: 0,0:05:22.77,0:05:25.14,Default,,0000,0000,0000,,And just to understand it a little bit better.
Dialogue: 0,0:05:25.14,0:05:28.01,Default,,0000,0000,0000,,Let's talk about those fundamental elements.
Dialogue: 0,0:05:28.01,0:05:31.82,Default,,0000,0000,0000,,So you have the proton.
Dialogue: 0,0:05:31.82,0:05:35.52,Default,,0000,0000,0000,,And the proton is actually the defining
Dialogue: 0,0:05:35.52,0:05:38.00,Default,,0000,0000,0000,,-- the number of protons in the nucleus of an atom
Dialogue: 0,0:05:38.00,0:05:40.10,Default,,0000,0000,0000,,and I'll talk about the nucleus in a second --
Dialogue: 0,0:05:40.10,0:05:42.97,Default,,0000,0000,0000,,that is what defines the element.
Dialogue: 0,0:05:42.97,0:05:45.49,Default,,0000,0000,0000,,So this is what defines an element.
Dialogue: 0,0:05:45.49,0:05:47.33,Default,,0000,0000,0000,,When you look at the periodic table right here,
Dialogue: 0,0:05:47.33,0:05:50.15,Default,,0000,0000,0000,,they are actually written in order of atomic number,
Dialogue: 0,0:05:50.15,0:05:51.58,Default,,0000,0000,0000,,and the atomic number is
Dialogue: 0,0:05:51.58,0:05:54.67,Default,,0000,0000,0000,,literally just the number of protons in the element.
Dialogue: 0,0:05:54.67,0:05:58.67,Default,,0000,0000,0000,,So by definition, hydrogen has 1 proton.
Dialogue: 0,0:05:58.67,0:06:02.80,Default,,0000,0000,0000,,Helium has 2 protons. Carbon has 6 protons.
Dialogue: 0,0:06:02.80,0:06:05.33,Default,,0000,0000,0000,,You cannot have carbon with 7 protons.
Dialogue: 0,0:06:05.33,0:06:07.17,Default,,0000,0000,0000,,If you did, it would be nitrogen,
Dialogue: 0,0:06:07.17,0:06:09.23,Default,,0000,0000,0000,,It would not be carbon anymore.
Dialogue: 0,0:06:09.23,0:06:10.59,Default,,0000,0000,0000,,Oxygen has 8 protons.
Dialogue: 0,0:06:10.59,0:06:12.67,Default,,0000,0000,0000,,If somehow you were to add another proton to there,
Dialogue: 0,0:06:12.67,0:06:14.05,Default,,0000,0000,0000,,it wouldn't be oxygen anymore.
Dialogue: 0,0:06:14.05,0:06:18.33,Default,,0000,0000,0000,,It would be fluorine. So it defines the element.
Dialogue: 0,0:06:18.33,0:06:20.07,Default,,0000,0000,0000,,It defines the element.
Dialogue: 0,0:06:20.07,0:06:22.97,Default,,0000,0000,0000,,And the atomic number, the number of protons,
Dialogue: 0,0:06:22.97,0:06:25.45,Default,,0000,0000,0000,,the number of protons -- and remember,
Dialogue: 0,0:06:25.45,0:06:27.67,Default,,0000,0000,0000,,that's the number that's written right at the top here
Dialogue: 0,0:06:27.67,0:06:30.12,Default,,0000,0000,0000,,for each of these elements in the periodic table
Dialogue: 0,0:06:30.12,0:06:31.53,Default,,0000,0000,0000,,-- the number of protons
Dialogue: 0,0:06:31.53,0:06:34.13,Default,,0000,0000,0000,,is equal to the atomic number.
Dialogue: 0,0:06:34.13,0:06:36.85,Default,,0000,0000,0000,,Is equal to the atomic number.
Dialogue: 0,0:06:36.87,0:06:38.86,Default,,0000,0000,0000,,And they put that number up here because that is
Dialogue: 0,0:06:38.86,0:06:42.22,Default,,0000,0000,0000,,the defining characteristic of an element.
Dialogue: 0,0:06:42.22,0:06:46.13,Default,,0000,0000,0000,,The other two constituents of an atom
Dialogue: 0,0:06:46.13,0:06:47.70,Default,,0000,0000,0000,,-- I guess we could call it that way --
Dialogue: 0,0:06:47.70,0:06:55.12,Default,,0000,0000,0000,,are the electron and the neutron.
Dialogue: 0,0:06:55.12,0:06:57.54,Default,,0000,0000,0000,,And the model you can start to build in your head
Dialogue: 0,0:06:57.54,0:07:00.42,Default,,0000,0000,0000,,-- and this model, as we go through chemistry we'll see,
Dialogue: 0,0:07:00.42,0:07:02.83,Default,,0000,0000,0000,,it will get a little bit more abstract
Dialogue: 0,0:07:02.83,0:07:04.82,Default,,0000,0000,0000,,and really hard to conceptualize --
Dialogue: 0,0:07:04.82,0:07:06.55,Default,,0000,0000,0000,,but one way to think about it is
Dialogue: 0,0:07:06.55,0:07:08.35,Default,,0000,0000,0000,,you have the protons and the neutrons
Dialogue: 0,0:07:08.35,0:07:09.82,Default,,0000,0000,0000,,that are the center of the atom.
Dialogue: 0,0:07:09.82,0:07:11.60,Default,,0000,0000,0000,,They are the nucleus of the atom.
Dialogue: 0,0:07:11.60,0:07:14.87,Default,,0000,0000,0000,,So for example, carbon, we know, has 6 protons.
Dialogue: 0,0:07:14.87,0:07:19.07,Default,,0000,0000,0000,,So one, two, three, four, five, six.
Dialogue: 0,0:07:19.07,0:07:22.38,Default,,0000,0000,0000,,Carbon 12, which is a version of carbon,
Dialogue: 0,0:07:22.38,0:07:24.20,Default,,0000,0000,0000,,will also have 6 neutrons.
Dialogue: 0,0:07:24.20,0:07:25.75,Default,,0000,0000,0000,,You can have versions of carbon
Dialogue: 0,0:07:25.75,0:07:28.02,Default,,0000,0000,0000,,that have a different number of neutrons.
Dialogue: 0,0:07:28.02,0:07:30.11,Default,,0000,0000,0000,,So the neutrons can change, the electrons can change,
Dialogue: 0,0:07:30.11,0:07:31.73,Default,,0000,0000,0000,,you can still have the same element.
Dialogue: 0,0:07:31.73,0:07:33.27,Default,,0000,0000,0000,,The protons can't change.
Dialogue: 0,0:07:33.27,0:07:35.90,Default,,0000,0000,0000,,You change the protons, you got a different element.
Dialogue: 0,0:07:35.90,0:07:39.20,Default,,0000,0000,0000,,So let me draw a carbon 12 nucleus.
Dialogue: 0,0:07:39.20,0:07:43.20,Default,,0000,0000,0000,,So one, two, three, four, five, six.
Dialogue: 0,0:07:43.20,0:07:46.49,Default,,0000,0000,0000,,So this right here is the nucleus of carbon 12.
Dialogue: 0,0:07:46.49,0:07:48.33,Default,,0000,0000,0000,,And sometimes it will be written like this.
Dialogue: 0,0:07:48.33,0:07:51.13,Default,,0000,0000,0000,,And sometimes they will actually write
Dialogue: 0,0:07:51.13,0:07:53.83,Default,,0000,0000,0000,,the number of protons as well.
Dialogue: 0,0:07:53.83,0:07:56.13,Default,,0000,0000,0000,,And the reason why we write it carbon 12
Dialogue: 0,0:07:56.13,0:07:58.68,Default,,0000,0000,0000,,-- you know I counted out 6 neutrons --
Dialogue: 0,0:07:58.68,0:08:00.38,Default,,0000,0000,0000,,is that this is the total
Dialogue: 0,0:08:00.38,0:08:03.68,Default,,0000,0000,0000,,you could view this as the total number of
Dialogue: 0,0:08:03.68,0:08:04.74,Default,,0000,0000,0000,,-- one way to view it,
Dialogue: 0,0:08:04.74,0:08:06.40,Default,,0000,0000,0000,,and we'll get a little bit of nuance in the future
Dialogue: 0,0:08:06.40,0:08:07.77,Default,,0000,0000,0000,,-- is that this is the total number
Dialogue: 0,0:08:07.77,0:08:11.84,Default,,0000,0000,0000,,of protons and neutrons inside of its nucleus.
Dialogue: 0,0:08:11.84,0:08:15.24,Default,,0000,0000,0000,,And this carbon by definition has an atomic number of 6,
Dialogue: 0,0:08:15.24,0:08:16.63,Default,,0000,0000,0000,,but we can rewrite it here
Dialogue: 0,0:08:16.63,0:08:18.60,Default,,0000,0000,0000,,just so that we can remind ourselves.
Dialogue: 0,0:08:18.60,0:08:21.34,Default,,0000,0000,0000,,So at the center of the carbon atom we have this nucleus.
Dialogue: 0,0:08:21.34,0:08:24.86,Default,,0000,0000,0000,,And carbon 12 will have 6 protons and 6 neutrons.
Dialogue: 0,0:08:24.86,0:08:27.50,Default,,0000,0000,0000,,Another version of carbon, carbon 14, will still have
Dialogue: 0,0:08:27.50,0:08:30.91,Default,,0000,0000,0000,,6 protons, but then it would have 8 neutrons.
Dialogue: 0,0:08:30.91,0:08:32.47,Default,,0000,0000,0000,,So the number of neutrons can change,
Dialogue: 0,0:08:32.47,0:08:34.61,Default,,0000,0000,0000,,but this is carbon 12 right over here.
Dialogue: 0,0:08:34.61,0:08:36.84,Default,,0000,0000,0000,,And if carbon 12 is neutral --
Dialogue: 0,0:08:36.84,0:08:40.66,Default,,0000,0000,0000,,and I'll give a little nuance on this word in a second as well --
Dialogue: 0,0:08:40.66,0:08:43.20,Default,,0000,0000,0000,,if it's neutral it will also have 6 electrons.
Dialogue: 0,0:08:43.20,0:08:45.40,Default,,0000,0000,0000,,So let me draw those 6 electrons.
Dialogue: 0,0:08:45.40,0:08:49.47,Default,,0000,0000,0000,,One, two, three, four, five, six.
Dialogue: 0,0:08:49.47,0:08:51.84,Default,,0000,0000,0000,,And one way -- and this is maybe the first order way
Dialogue: 0,0:08:51.84,0:08:54.63,Default,,0000,0000,0000,,of thinking about the relationship
Dialogue: 0,0:08:54.63,0:08:56.89,Default,,0000,0000,0000,,between the electrons and the nucleus --
Dialogue: 0,0:08:56.89,0:08:58.85,Default,,0000,0000,0000,,is that you can imagine the electrons
Dialogue: 0,0:08:58.85,0:09:00.84,Default,,0000,0000,0000,,are kind of moving around,
Dialogue: 0,0:09:00.84,0:09:02.96,Default,,0000,0000,0000,,buzzing around this nucleus.
Dialogue: 0,0:09:02.96,0:09:04.69,Default,,0000,0000,0000,,One model is you could kind of
Dialogue: 0,0:09:04.69,0:09:06.70,Default,,0000,0000,0000,,thinking of them as orbiting around the nucleus,
Dialogue: 0,0:09:06.70,0:09:08.00,Default,,0000,0000,0000,,but that's not quite right.
Dialogue: 0,0:09:08.00,0:09:10.50,Default,,0000,0000,0000,,They don't orbit the way that a planet, say,
Dialogue: 0,0:09:10.50,0:09:11.66,Default,,0000,0000,0000,,orbits around the Sun.
Dialogue: 0,0:09:11.66,0:09:13.75,Default,,0000,0000,0000,,But that's a good starting point.
Dialogue: 0,0:09:13.75,0:09:16.27,Default,,0000,0000,0000,,Another way is that they kind of jumping around the nucleus
Dialogue: 0,0:09:16.27,0:09:18.69,Default,,0000,0000,0000,,or they are buzzing around the nucleus.
Dialogue: 0,0:09:18.69,0:09:19.96,Default,,0000,0000,0000,,And that's just because
Dialogue: 0,0:09:19.96,0:09:22.07,Default,,0000,0000,0000,,reality just gets very strange at this level,
Dialogue: 0,0:09:22.07,0:09:23.54,Default,,0000,0000,0000,,and we'll actually have to get to quantum physics
Dialogue: 0,0:09:23.54,0:09:26.41,Default,,0000,0000,0000,,to really understand what the electron is doing.
Dialogue: 0,0:09:26.41,0:09:29.19,Default,,0000,0000,0000,,But a first mental model in your head is
Dialogue: 0,0:09:29.19,0:09:32.40,Default,,0000,0000,0000,,at the center of this atom, of this carbon 12 atom,
Dialogue: 0,0:09:32.40,0:09:34.07,Default,,0000,0000,0000,,you have this nucleus.
Dialogue: 0,0:09:34.07,0:09:36.64,Default,,0000,0000,0000,,You have this nucleus right over there.
Dialogue: 0,0:09:36.64,0:09:40.73,Default,,0000,0000,0000,,And these electrons are jumping around this nucleus.
Dialogue: 0,0:09:40.73,0:09:43.01,Default,,0000,0000,0000,,And the reason why these electrons
Dialogue: 0,0:09:43.01,0:09:45.14,Default,,0000,0000,0000,,don't just go off away from this nucleus,
Dialogue: 0,0:09:45.14,0:09:47.20,Default,,0000,0000,0000,,why they are kind of bound to this nucleus,
Dialogue: 0,0:09:47.20,0:09:49.31,Default,,0000,0000,0000,,and they form part of this atom,
Dialogue: 0,0:09:49.31,0:09:54.58,Default,,0000,0000,0000,,is that protons have a positive charge,
Dialogue: 0,0:09:54.58,0:09:57.92,Default,,0000,0000,0000,,and electrons have a negative charge.
Dialogue: 0,0:09:57.92,0:10:02.48,Default,,0000,0000,0000,,And it's one of these properties of these fundamental particles.
Dialogue: 0,0:10:02.48,0:10:03.62,Default,,0000,0000,0000,,When you start thinking about
Dialogue: 0,0:10:03.62,0:10:05.47,Default,,0000,0000,0000,,what is a charge fundamentally other than a label,
Dialogue: 0,0:10:05.47,0:10:06.87,Default,,0000,0000,0000,,and it starts to get kind of deep.
Dialogue: 0,0:10:06.87,0:10:08.40,Default,,0000,0000,0000,,But the one thing that we know,
Dialogue: 0,0:10:08.40,0:10:10.70,Default,,0000,0000,0000,,when we talk about electro-magnetic force,
Dialogue: 0,0:10:10.70,0:10:13.15,Default,,0000,0000,0000,,is that unlike charges attract each other.
Dialogue: 0,0:10:13.15,0:10:14.96,Default,,0000,0000,0000,,So the best way to think about it is:
Dialogue: 0,0:10:14.96,0:10:16.55,Default,,0000,0000,0000,,protons and electrons,
Dialogue: 0,0:10:16.55,0:10:18.13,Default,,0000,0000,0000,,because they have different charges,
Dialogue: 0,0:10:18.13,0:10:20.13,Default,,0000,0000,0000,,they attract each other.
Dialogue: 0,0:10:20.13,0:10:21.46,Default,,0000,0000,0000,,Neutrons are neutral,
Dialogue: 0,0:10:21.46,0:10:25.09,Default,,0000,0000,0000,,so they're really just sitting here inside of the nucleus,
Dialogue: 0,0:10:25.09,0:10:28.58,Default,,0000,0000,0000,,and they do affect the properties on some level,
Dialogue: 0,0:10:28.58,0:10:33.15,Default,,0000,0000,0000,,for some atoms of certain elements.
Dialogue: 0,0:10:33.15,0:10:35.00,Default,,0000,0000,0000,,But the reason why we have the electrons
Dialogue: 0,0:10:35.00,0:10:36.82,Default,,0000,0000,0000,,not just flying off on their own
Dialogue: 0,0:10:36.82,0:10:38.60,Default,,0000,0000,0000,,is because they are attracted.
Dialogue: 0,0:10:38.60,0:10:42.33,Default,,0000,0000,0000,,They are attracted towards the nucleus.
Dialogue: 0,0:10:42.33,0:10:45.07,Default,,0000,0000,0000,,And they also have an unbelievably high velocity
Dialogue: 0,0:10:45.07,0:10:47.14,Default,,0000,0000,0000,,-- it's actually hard for --
Dialogue: 0,0:10:47.14,0:10:48.45,Default,,0000,0000,0000,,we start touching once again
Dialogue: 0,0:10:48.45,0:10:51.55,Default,,0000,0000,0000,,on a very strange part of physics
Dialogue: 0,0:10:51.55,0:10:52.57,Default,,0000,0000,0000,,once we start talking about
Dialogue: 0,0:10:52.57,0:10:54.16,Default,,0000,0000,0000,,what an electron actually is doing
Dialogue: 0,0:10:54.16,0:10:55.95,Default,,0000,0000,0000,,-- but is has enough --
Dialogue: 0,0:10:55.95,0:10:56.84,Default,,0000,0000,0000,,I guess you could say
Dialogue: 0,0:10:56.84,0:10:57.92,Default,,0000,0000,0000,,it's jumping around enough
Dialogue: 0,0:10:57.92,0:11:00.73,Default,,0000,0000,0000,,that it doesn't want to just fall into the nucleus,
Dialogue: 0,0:11:00.73,0:11:02.87,Default,,0000,0000,0000,,I guess is one way of thinking about it.
Dialogue: 0,0:11:02.87,0:11:08.12,Default,,0000,0000,0000,,And so, I mentioned carbon 12 right over here
Dialogue: 0,0:11:08.12,0:11:09.77,Default,,0000,0000,0000,,defined by the number or protons.
Dialogue: 0,0:11:09.77,0:11:12.40,Default,,0000,0000,0000,,Oxygen would be defined by having 8 protons.
Dialogue: 0,0:11:12.40,0:11:16.47,Default,,0000,0000,0000,,But once again, electrons can interact with other electrons.
Dialogue: 0,0:11:16.47,0:11:18.65,Default,,0000,0000,0000,,They can be taken away by other atoms.
Dialogue: 0,0:11:18.65,0:11:21.02,Default,,0000,0000,0000,,And that actually forms
Dialogue: 0,0:11:21.02,0:11:23.27,Default,,0000,0000,0000,,a lot of our understanding of chemistry.
Dialogue: 0,0:11:23.27,0:11:25.100,Default,,0000,0000,0000,,It's based on how many electrons an atom has,
Dialogue: 0,0:11:25.100,0:11:27.60,Default,,0000,0000,0000,,or a certain element has.
Dialogue: 0,0:11:27.60,0:11:29.47,Default,,0000,0000,0000,,And how those electrons are configured,
Dialogue: 0,0:11:29.47,0:11:33.87,Default,,0000,0000,0000,,and how the electrons of other elements are configured,
Dialogue: 0,0:11:33.87,0:11:36.02,Default,,0000,0000,0000,,or maybe other atoms of that same element.
Dialogue: 0,0:11:36.02,0:11:41.27,Default,,0000,0000,0000,,We can start to predict how an atom of one element
Dialogue: 0,0:11:41.27,0:11:43.33,Default,,0000,0000,0000,,can react with another atom of that same element,
Dialogue: 0,0:11:43.33,0:11:46.73,Default,,0000,0000,0000,,or an atom of one element -- how it could react,
Dialogue: 0,0:11:46.73,0:11:49.70,Default,,0000,0000,0000,,or how it could bond, or not bond, or be attracted to,
Dialogue: 0,0:11:49.70,0:11:52.20,Default,,0000,0000,0000,,or repel another atom of another element.
Dialogue: 0,0:11:52.20,0:11:53.42,Default,,0000,0000,0000,,So for example,
Dialogue: 0,0:11:53.42,0:11:56.30,Default,,0000,0000,0000,,and we'll learn a lot more about this in the future,
Dialogue: 0,0:11:56.30,0:12:00.14,Default,,0000,0000,0000,,is: it is possible for another atom some place
Dialogue: 0,0:12:00.14,0:12:02.72,Default,,0000,0000,0000,,to swipe away an electron from a carbon,
Dialogue: 0,0:12:02.73,0:12:05.55,Default,,0000,0000,0000,,just because for whatever reason --
Dialogue: 0,0:12:05.55,0:12:10.34,Default,,0000,0000,0000,,and we'll talk about certain neutral atoms of certain elements
Dialogue: 0,0:12:10.34,0:12:13.72,Default,,0000,0000,0000,,have a larger affinity for electrons than others.
Dialogue: 0,0:12:13.72,0:12:15.22,Default,,0000,0000,0000,,So one, maybe one of those,
Dialogue: 0,0:12:15.22,0:12:17.16,Default,,0000,0000,0000,,swipes an electron away from a carbon,
Dialogue: 0,0:12:17.16,0:12:19.23,Default,,0000,0000,0000,,and then this carbon will be
Dialogue: 0,0:12:19.23,0:12:21.83,Default,,0000,0000,0000,,having less electrons than protons,
Dialogue: 0,0:12:21.83,0:12:25.14,Default,,0000,0000,0000,,so then we'll have 5 electrons and 6 protons.
Dialogue: 0,0:12:25.14,0:12:27.80,Default,,0000,0000,0000,,And then we'd have a net positive charge.
Dialogue: 0,0:12:27.80,0:12:30.04,Default,,0000,0000,0000,,So in this carbon 12, the first version I did,
Dialogue: 0,0:12:30.04,0:12:34.27,Default,,0000,0000,0000,,I had 6 protons, 6 electrons, the charges canceled out.
Dialogue: 0,0:12:34.27,0:12:36.55,Default,,0000,0000,0000,,If I lose an electron, then I only have 5 of these,
Dialogue: 0,0:12:36.55,0:12:38.93,Default,,0000,0000,0000,,and then I would have a net positive charge.
Dialogue: 0,0:12:38.93,0:12:40.78,Default,,0000,0000,0000,,And we're going to talk a lot more
Dialogue: 0,0:12:40.78,0:12:42.87,Default,,0000,0000,0000,,about all of this throughout the chemistry playlist,
Dialogue: 0,0:12:42.87,0:12:44.30,Default,,0000,0000,0000,,but hopefully you have an appreciation that
Dialogue: 0,0:12:44.30,0:12:46.13,Default,,0000,0000,0000,,this is already starting to get really cool.
Dialogue: 0,0:12:46.13,0:12:51.80,Default,,0000,0000,0000,,We can already get to this fundamental building block
Dialogue: 0,0:12:51.80,0:12:53.12,Default,,0000,0000,0000,,called the atom.
Dialogue: 0,0:12:53.12,0:12:54.92,Default,,0000,0000,0000,,And what's even neater is that
Dialogue: 0,0:12:54.92,0:12:56.76,Default,,0000,0000,0000,,this fundamental building block is built of
Dialogue: 0,0:12:56.76,0:12:58.67,Default,,0000,0000,0000,,even more fundamental building blocks.
Dialogue: 0,0:12:58.67,0:13:00.87,Default,,0000,0000,0000,,And these things can all be swapped around
Dialogue: 0,0:13:00.87,0:13:03.13,Default,,0000,0000,0000,,to change the properties of an atom,
Dialogue: 0,0:13:03.13,0:13:06.04,Default,,0000,0000,0000,,or even go from an atom of one element
Dialogue: 0,0:13:06.04,0:13:09.04,Default,,0000,0000,0000,,to an atom of another element.