[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.66,0:00:03.12,Default,,0000,0000,0000,,We humans have known,\Nfor thousands of years,
Dialogue: 0,0:00:03.12,0:00:05.34,Default,,0000,0000,0000,,just looking at our\Nenvironment around us,
Dialogue: 0,0:00:05.34,0:00:06.84,Default,,0000,0000,0000,,that there are\Ndifferent substances.
Dialogue: 0,0:00:06.84,0:00:08.60,Default,,0000,0000,0000,,And these different\Nsubstances tend
Dialogue: 0,0:00:08.60,0:00:10.12,Default,,0000,0000,0000,,to have different properties.
Dialogue: 0,0:00:10.12,0:00:11.47,Default,,0000,0000,0000,,And not only do they have\Ndifferent properties,
Dialogue: 0,0:00:11.47,0:00:13.40,Default,,0000,0000,0000,,one might reflect\Nlight in a certain way,
Dialogue: 0,0:00:13.40,0:00:16.23,Default,,0000,0000,0000,,or not reflect light, or\Nbe a certain color, or at
Dialogue: 0,0:00:16.23,0:00:20.39,Default,,0000,0000,0000,,a certain temperature, be\Nliquid or gas, or be a solid.
Dialogue: 0,0:00:20.39,0:00:22.29,Default,,0000,0000,0000,,But we also start\Nto observe how they
Dialogue: 0,0:00:22.29,0:00:25.03,Default,,0000,0000,0000,,react with each other in\Ncertain circumstances.
Dialogue: 0,0:00:25.03,0:00:27.41,Default,,0000,0000,0000,,And here's pictures of\Nsome of these substances.
Dialogue: 0,0:00:27.41,0:00:29.07,Default,,0000,0000,0000,,This right here is carbon.
Dialogue: 0,0:00:29.07,0:00:31.65,Default,,0000,0000,0000,,And this is in\Nits graphite form.
Dialogue: 0,0:00:31.65,0:00:33.91,Default,,0000,0000,0000,,This right here is lead.
Dialogue: 0,0:00:33.91,0:00:36.03,Default,,0000,0000,0000,,This right here is gold.
Dialogue: 0,0:00:36.03,0:00:38.75,Default,,0000,0000,0000,,And all of the ones that I've\Nshown pictures of, here--
Dialogue: 0,0:00:38.75,0:00:41.72,Default,,0000,0000,0000,,and I got them all from this\Nwebsite, right over there--
Dialogue: 0,0:00:41.72,0:00:43.46,Default,,0000,0000,0000,,all of these are in\Ntheir solid form.
Dialogue: 0,0:00:43.46,0:00:45.83,Default,,0000,0000,0000,,But we also know that\Nit looks like there's
Dialogue: 0,0:00:45.83,0:00:49.24,Default,,0000,0000,0000,,certain types of air, and\Ncertain types of air particles.
Dialogue: 0,0:00:49.24,0:00:51.09,Default,,0000,0000,0000,,And depending on what\Ntype of air particles
Dialogue: 0,0:00:51.09,0:00:55.59,Default,,0000,0000,0000,,you're looking at, whether it\Nis carbon or oxygen or nitrogen,
Dialogue: 0,0:00:55.59,0:00:57.79,Default,,0000,0000,0000,,that seems to have different\Ntypes of properties.
Dialogue: 0,0:00:57.79,0:00:59.67,Default,,0000,0000,0000,,Or there are other things\Nthat can be liquid.
Dialogue: 0,0:00:59.67,0:01:01.66,Default,,0000,0000,0000,,Or even if you raise the\Ntemperature high enough
Dialogue: 0,0:01:01.66,0:01:02.36,Default,,0000,0000,0000,,on these things.
Dialogue: 0,0:01:02.36,0:01:04.48,Default,,0000,0000,0000,,You could, if you raise\Nthe temperature high enough
Dialogue: 0,0:01:04.48,0:01:06.44,Default,,0000,0000,0000,,on gold or lead, you\Ncould get a liquid.
Dialogue: 0,0:01:06.44,0:01:10.36,Default,,0000,0000,0000,,Or if you, kind of, if\Nyou burn this carbon,
Dialogue: 0,0:01:10.36,0:01:12.02,Default,,0000,0000,0000,,you can get it to\Na gaseous state.
Dialogue: 0,0:01:12.02,0:01:13.69,Default,,0000,0000,0000,,You can release it\Ninto the atmosphere.
Dialogue: 0,0:01:13.69,0:01:14.88,Default,,0000,0000,0000,,You can break its structure.
Dialogue: 0,0:01:14.88,0:01:18.53,Default,,0000,0000,0000,,So these are things that we've\Nall, kind of, that humanity
Dialogue: 0,0:01:18.53,0:01:21.00,Default,,0000,0000,0000,,has observed for\Nthousands of years.
Dialogue: 0,0:01:21.00,0:01:22.53,Default,,0000,0000,0000,,But it leads to a\Nnatural question
Dialogue: 0,0:01:22.53,0:01:24.42,Default,,0000,0000,0000,,that used to be a\Nphilosophical question.
Dialogue: 0,0:01:24.42,0:01:26.79,Default,,0000,0000,0000,,But now we can answer\Nit a little bit better.
Dialogue: 0,0:01:26.79,0:01:31.32,Default,,0000,0000,0000,,And that question is, if you\Nkeep breaking down this carbon,
Dialogue: 0,0:01:31.32,0:01:33.97,Default,,0000,0000,0000,,into smaller and\Nsmaller chunks, is there
Dialogue: 0,0:01:33.97,0:01:38.93,Default,,0000,0000,0000,,some smallest chunk, some\Nsmallest unit, of this stuff,
Dialogue: 0,0:01:38.93,0:01:43.31,Default,,0000,0000,0000,,of this substance, that still\Nhas the properties of carbon?
Dialogue: 0,0:01:43.31,0:01:44.73,Default,,0000,0000,0000,,And if you were\Nto, somehow, break
Dialogue: 0,0:01:44.73,0:01:46.27,Default,,0000,0000,0000,,that even further,\Nsomehow, you would
Dialogue: 0,0:01:46.27,0:01:48.27,Default,,0000,0000,0000,,lose the properties\Nof the carbon.
Dialogue: 0,0:01:48.27,0:01:50.38,Default,,0000,0000,0000,,And the answer is, there is.
Dialogue: 0,0:01:50.38,0:01:52.03,Default,,0000,0000,0000,,And so just to get\Nour terminology,
Dialogue: 0,0:01:52.03,0:01:54.94,Default,,0000,0000,0000,,we call these\Ndifferent substances--
Dialogue: 0,0:01:54.94,0:01:58.07,Default,,0000,0000,0000,,these pure substances that\Nhave these specific properties
Dialogue: 0,0:01:58.07,0:01:59.96,Default,,0000,0000,0000,,at certain\Ntemperatures and react
Dialogue: 0,0:01:59.96,0:02:02.02,Default,,0000,0000,0000,,in certain ways-- we\Ncall them elements.
Dialogue: 0,0:02:05.21,0:02:06.47,Default,,0000,0000,0000,,Carbon is an element.
Dialogue: 0,0:02:06.47,0:02:07.57,Default,,0000,0000,0000,,Lead is an element.
Dialogue: 0,0:02:07.57,0:02:08.91,Default,,0000,0000,0000,,Gold is an element.
Dialogue: 0,0:02:08.91,0:02:10.95,Default,,0000,0000,0000,,You might say that\Nwater is an element.
Dialogue: 0,0:02:10.95,0:02:13.83,Default,,0000,0000,0000,,And in history, people\Nhave referred to water
Dialogue: 0,0:02:13.83,0:02:14.41,Default,,0000,0000,0000,,as an element.
Dialogue: 0,0:02:14.41,0:02:18.25,Default,,0000,0000,0000,,But now we know that water is\Nmade up of more basic elements.
Dialogue: 0,0:02:18.25,0:02:21.10,Default,,0000,0000,0000,,It's made of oxygen\Nand of hydrogen.
Dialogue: 0,0:02:21.10,0:02:25.12,Default,,0000,0000,0000,,And all of our elements\Nare listed here
Dialogue: 0,0:02:25.12,0:02:27.83,Default,,0000,0000,0000,,in the Periodic\NTable of Elements.
Dialogue: 0,0:02:27.83,0:02:30.45,Default,,0000,0000,0000,,C stands for carbon-- I'm just\Ngoing through the ones that
Dialogue: 0,0:02:30.45,0:02:33.28,Default,,0000,0000,0000,,are very relevant to humanity,\Nbut over time, you'll
Dialogue: 0,0:02:33.28,0:02:35.71,Default,,0000,0000,0000,,probably familiarize\Nyourself with all of these.
Dialogue: 0,0:02:35.71,0:02:36.61,Default,,0000,0000,0000,,This is oxygen.
Dialogue: 0,0:02:36.61,0:02:38.02,Default,,0000,0000,0000,,This is nitrogen.
Dialogue: 0,0:02:38.02,0:02:40.14,Default,,0000,0000,0000,,This is silicon.
Dialogue: 0,0:02:40.14,0:02:42.09,Default,,0000,0000,0000,,Au is gold.
Dialogue: 0,0:02:42.09,0:02:43.28,Default,,0000,0000,0000,,This is lead.
Dialogue: 0,0:02:43.28,0:02:49.38,Default,,0000,0000,0000,,And that most basic unit, of any\Nof these elements, is the atom.
Dialogue: 0,0:02:52.62,0:02:55.05,Default,,0000,0000,0000,,So if you were to keep\Ndigging in, and keep
Dialogue: 0,0:02:55.05,0:02:56.94,Default,,0000,0000,0000,,taking smaller and\Nsmaller chunks of this,
Dialogue: 0,0:02:56.94,0:02:59.74,Default,,0000,0000,0000,,eventually, you would\Nget to a carbon atom.
Dialogue: 0,0:02:59.74,0:03:01.53,Default,,0000,0000,0000,,Do the same thing over\Nhere, eventually you
Dialogue: 0,0:03:01.53,0:03:02.62,Default,,0000,0000,0000,,would get to a gold atom.
Dialogue: 0,0:03:02.62,0:03:04.49,Default,,0000,0000,0000,,You did the same thing\Nover here, eventually,
Dialogue: 0,0:03:04.49,0:03:05.86,Default,,0000,0000,0000,,you would get\Nsome-- this little,
Dialogue: 0,0:03:05.86,0:03:08.00,Default,,0000,0000,0000,,small, for lack of a\Nbetter word, particle,
Dialogue: 0,0:03:08.00,0:03:09.45,Default,,0000,0000,0000,,that you would call a lead atom.
Dialogue: 0,0:03:09.45,0:03:11.24,Default,,0000,0000,0000,,And you wouldn't be\Nable to break that down
Dialogue: 0,0:03:11.24,0:03:13.56,Default,,0000,0000,0000,,anymore and still\Ncall that lead,
Dialogue: 0,0:03:13.56,0:03:17.11,Default,,0000,0000,0000,,for it to still have\Nthe properties of lead.
Dialogue: 0,0:03:17.11,0:03:19.49,Default,,0000,0000,0000,,And just to give you an idea--\Nthis is really something
Dialogue: 0,0:03:19.49,0:03:21.60,Default,,0000,0000,0000,,that I have trouble\Nimagining-- is
Dialogue: 0,0:03:21.60,0:03:24.69,Default,,0000,0000,0000,,that atoms are\Nunbelievably small, really
Dialogue: 0,0:03:24.69,0:03:26.22,Default,,0000,0000,0000,,unimaginably small.
Dialogue: 0,0:03:26.22,0:03:27.75,Default,,0000,0000,0000,,So for example, carbon.
Dialogue: 0,0:03:27.75,0:03:29.55,Default,,0000,0000,0000,,My hair is also\Nmade out of carbon.
Dialogue: 0,0:03:29.55,0:03:33.32,Default,,0000,0000,0000,,In fact, most of me\Nis made out of carbon.
Dialogue: 0,0:03:33.32,0:03:36.69,Default,,0000,0000,0000,,In fact, most of all living\Nthings are made out of carbon.
Dialogue: 0,0:03:36.69,0:03:40.84,Default,,0000,0000,0000,,And so if you took my hair--\Nand so my hair is carbon,
Dialogue: 0,0:03:40.84,0:03:42.26,Default,,0000,0000,0000,,my hair is mostly carbon.
Dialogue: 0,0:03:42.26,0:03:43.97,Default,,0000,0000,0000,,So if you took my\Nhair-- right over here,
Dialogue: 0,0:03:43.97,0:03:46.08,Default,,0000,0000,0000,,my hair isn't yellow,\Nbut it contrasts nicely
Dialogue: 0,0:03:46.08,0:03:46.70,Default,,0000,0000,0000,,with the black.
Dialogue: 0,0:03:46.70,0:03:48.28,Default,,0000,0000,0000,,My hair is black,\Nbut if I did that,
Dialogue: 0,0:03:48.28,0:03:50.27,Default,,0000,0000,0000,,you wouldn't be able to\Nsee it on the screen.
Dialogue: 0,0:03:50.27,0:03:51.77,Default,,0000,0000,0000,,But if you took my\Nhair, here, and I
Dialogue: 0,0:03:51.77,0:03:55.82,Default,,0000,0000,0000,,were to ask you, how many\Ncarbon atoms wide is my hair?
Dialogue: 0,0:03:55.82,0:03:57.87,Default,,0000,0000,0000,,So, if you took a cross\Nsection of my hair, not
Dialogue: 0,0:03:57.87,0:04:00.04,Default,,0000,0000,0000,,the length, the\Nwidth of my hair,
Dialogue: 0,0:04:00.04,0:04:03.38,Default,,0000,0000,0000,,and said, how many carbon\Natoms wide is that?
Dialogue: 0,0:04:03.38,0:04:04.80,Default,,0000,0000,0000,,And you might\Nguess, oh, you know,
Dialogue: 0,0:04:04.80,0:04:07.54,Default,,0000,0000,0000,,Sal already told me\Nthey're very small.
Dialogue: 0,0:04:07.54,0:04:10.02,Default,,0000,0000,0000,,So maybe there's 1,000 carbon\Natoms there, or 10,000,
Dialogue: 0,0:04:10.02,0:04:10.78,Default,,0000,0000,0000,,or 100,000.
Dialogue: 0,0:04:10.78,0:04:12.00,Default,,0000,0000,0000,,I would say, no.
Dialogue: 0,0:04:12.00,0:04:14.54,Default,,0000,0000,0000,,There are 1 million\Ncarbon atoms,
Dialogue: 0,0:04:14.54,0:04:17.58,Default,,0000,0000,0000,,or you could string 1\Nmillion carbon atoms
Dialogue: 0,0:04:17.58,0:04:21.31,Default,,0000,0000,0000,,across the width of\Nthe average human hair.
Dialogue: 0,0:04:21.31,0:04:22.73,Default,,0000,0000,0000,,That's obviously\Nan approximation.
Dialogue: 0,0:04:22.73,0:04:23.97,Default,,0000,0000,0000,,It's not exactly 1 million.
Dialogue: 0,0:04:23.97,0:04:26.86,Default,,0000,0000,0000,,But that gives you a sense\Nof how small an atom is.
Dialogue: 0,0:04:26.86,0:04:28.62,Default,,0000,0000,0000,,You know, pluck a\Nhair out of your head,
Dialogue: 0,0:04:28.62,0:04:31.30,Default,,0000,0000,0000,,and just imagine\Nputting a million things
Dialogue: 0,0:04:31.30,0:04:34.44,Default,,0000,0000,0000,,next to each other,\Nacross the hair.
Dialogue: 0,0:04:34.44,0:04:37.45,Default,,0000,0000,0000,,Not the length of the hair,\Nthe width of the hair.
Dialogue: 0,0:04:37.45,0:04:39.36,Default,,0000,0000,0000,,It's even hard to see\Nthe width of a hair,
Dialogue: 0,0:04:39.36,0:04:41.11,Default,,0000,0000,0000,,and there would be a\Nmillion carbon atoms,
Dialogue: 0,0:04:41.11,0:04:43.18,Default,,0000,0000,0000,,just going along it.
Dialogue: 0,0:04:43.18,0:04:46.86,Default,,0000,0000,0000,,Now it would be pretty\Ncool, in and of itself,
Dialogue: 0,0:04:46.86,0:04:50.84,Default,,0000,0000,0000,,that we do know that there\Nis this most basic building
Dialogue: 0,0:04:50.84,0:04:54.22,Default,,0000,0000,0000,,block of carbon, this most basic\Nbuilding block of any element.
Dialogue: 0,0:04:54.22,0:04:57.13,Default,,0000,0000,0000,,But what's even neater is\Nthat, those basic building
Dialogue: 0,0:04:57.13,0:04:58.57,Default,,0000,0000,0000,,blocks are related\Nto each other.
Dialogue: 0,0:04:58.57,0:05:02.40,Default,,0000,0000,0000,,That a carbon atom is made\Nup of even more fundamental
Dialogue: 0,0:05:02.40,0:05:02.95,Default,,0000,0000,0000,,particles.
Dialogue: 0,0:05:02.95,0:05:07.67,Default,,0000,0000,0000,,A gold atom is made up even\Nmore fundamental particles.
Dialogue: 0,0:05:07.67,0:05:09.17,Default,,0000,0000,0000,,And depending-- and\Nthey're actually
Dialogue: 0,0:05:09.17,0:05:12.87,Default,,0000,0000,0000,,defined by the arrangement of\Nthose fundamental particles.
Dialogue: 0,0:05:12.87,0:05:15.43,Default,,0000,0000,0000,,And if you were to change the\Nnumber of fundamental particles
Dialogue: 0,0:05:15.43,0:05:18.43,Default,,0000,0000,0000,,you have, you could change the\Nproperties of the element, how
Dialogue: 0,0:05:18.43,0:05:22.81,Default,,0000,0000,0000,,it would react, or you could\Neven change the element itself.
Dialogue: 0,0:05:22.81,0:05:25.48,Default,,0000,0000,0000,,And just to understand\Nit a little bit better,
Dialogue: 0,0:05:25.48,0:05:28.26,Default,,0000,0000,0000,,let's talk about those\Nfundamental elements.
Dialogue: 0,0:05:28.26,0:05:30.36,Default,,0000,0000,0000,,So you have the proton.
Dialogue: 0,0:05:33.02,0:05:36.00,Default,,0000,0000,0000,,And the proton is actually\Nthe defining-- the number
Dialogue: 0,0:05:36.00,0:05:38.34,Default,,0000,0000,0000,,of protons in the\Nnucleus of an atom,
Dialogue: 0,0:05:38.34,0:05:40.61,Default,,0000,0000,0000,,and I'll talk about the\Nnucleus in a second-- that
Dialogue: 0,0:05:40.61,0:05:43.01,Default,,0000,0000,0000,,is what defines the element.
Dialogue: 0,0:05:43.01,0:05:45.70,Default,,0000,0000,0000,,So this is what\Ndefines an element.
Dialogue: 0,0:05:45.70,0:05:47.66,Default,,0000,0000,0000,,When you look at the\Nperiodic table right here,
Dialogue: 0,0:05:47.66,0:05:50.49,Default,,0000,0000,0000,,they're actually written\Nin order of atomic number.
Dialogue: 0,0:05:50.49,0:05:52.25,Default,,0000,0000,0000,,And the atomic\Nnumber is, literally,
Dialogue: 0,0:05:52.25,0:05:55.14,Default,,0000,0000,0000,,just the number of\Nprotons in the element.
Dialogue: 0,0:05:55.14,0:05:58.95,Default,,0000,0000,0000,,So by definition,\Nhydrogen has one proton,
Dialogue: 0,0:05:58.95,0:06:03.12,Default,,0000,0000,0000,,helium has two protons,\Ncarbon has six protons.
Dialogue: 0,0:06:03.12,0:06:05.44,Default,,0000,0000,0000,,You cannot have carbon\Nwith seven protons.
Dialogue: 0,0:06:05.44,0:06:07.15,Default,,0000,0000,0000,,If you did, it\Nwould be nitrogen.
Dialogue: 0,0:06:07.15,0:06:09.30,Default,,0000,0000,0000,,It would not be carbon anymore.
Dialogue: 0,0:06:09.30,0:06:10.73,Default,,0000,0000,0000,,Oxygen has eight protons.
Dialogue: 0,0:06:10.73,0:06:12.94,Default,,0000,0000,0000,,If, somehow, you were to\Nadd another proton to there,
Dialogue: 0,0:06:12.94,0:06:14.68,Default,,0000,0000,0000,,it wouldn't be oxygen anymore.
Dialogue: 0,0:06:14.68,0:06:16.37,Default,,0000,0000,0000,,It would be fluorine.
Dialogue: 0,0:06:16.37,0:06:17.70,Default,,0000,0000,0000,,So it defines the element.
Dialogue: 0,0:06:20.24,0:06:22.45,Default,,0000,0000,0000,,And the atomic\Nnumber, the number
Dialogue: 0,0:06:22.45,0:06:25.55,Default,,0000,0000,0000,,of protons-- and\Nremember, that's
Dialogue: 0,0:06:25.55,0:06:27.34,Default,,0000,0000,0000,,the number that's\Nwritten right at the top,
Dialogue: 0,0:06:27.34,0:06:30.26,Default,,0000,0000,0000,,here, for each of these\Nelements in the periodic table--
Dialogue: 0,0:06:30.26,0:06:33.01,Default,,0000,0000,0000,,the number of protons is\Nequal to the atomic number.
Dialogue: 0,0:06:36.70,0:06:38.08,Default,,0000,0000,0000,,And they put that\Nnumber up here,
Dialogue: 0,0:06:38.08,0:06:42.16,Default,,0000,0000,0000,,because that is the defining\Ncharacteristic of an element.
Dialogue: 0,0:06:42.16,0:06:46.05,Default,,0000,0000,0000,,The other two constituents\Nof an atom-- I
Dialogue: 0,0:06:46.05,0:06:47.43,Default,,0000,0000,0000,,guess we could\Ncall it that way--
Dialogue: 0,0:06:47.43,0:06:51.78,Default,,0000,0000,0000,,are the electron\Nand the neutron.
Dialogue: 0,0:06:55.39,0:06:57.11,Default,,0000,0000,0000,,And the model you\Ncan start to build
Dialogue: 0,0:06:57.11,0:07:01.32,Default,,0000,0000,0000,,in your head-- and this model,\Nas we go through chemistry,
Dialogue: 0,0:07:01.32,0:07:03.69,Default,,0000,0000,0000,,it'll get a little bit more\Nabstract and really hard
Dialogue: 0,0:07:03.69,0:07:04.98,Default,,0000,0000,0000,,to conceptualize.
Dialogue: 0,0:07:04.98,0:07:06.35,Default,,0000,0000,0000,,But one way to\Nthink about it is,
Dialogue: 0,0:07:06.35,0:07:08.43,Default,,0000,0000,0000,,you have the protons\Nand the neutrons that
Dialogue: 0,0:07:08.43,0:07:09.85,Default,,0000,0000,0000,,are at the center of the atom.
Dialogue: 0,0:07:09.85,0:07:11.71,Default,,0000,0000,0000,,They're the nucleus of the atom.
Dialogue: 0,0:07:11.71,0:07:15.06,Default,,0000,0000,0000,,So for example, carbon,\Nwe know, has six protons.
Dialogue: 0,0:07:15.06,0:07:19.66,Default,,0000,0000,0000,,So one, two, three,\Nfour, five, six.
Dialogue: 0,0:07:19.66,0:07:22.42,Default,,0000,0000,0000,,Carbon-12, which is\Na version of carbon,
Dialogue: 0,0:07:22.42,0:07:24.11,Default,,0000,0000,0000,,will also have six neutrons.
Dialogue: 0,0:07:24.11,0:07:26.10,Default,,0000,0000,0000,,You can have versions\Nof carbon that
Dialogue: 0,0:07:26.10,0:07:27.94,Default,,0000,0000,0000,,have a different\Nnumber of neutrons.
Dialogue: 0,0:07:27.94,0:07:30.33,Default,,0000,0000,0000,,So the neutrons can change,\Nthe electrons can change,
Dialogue: 0,0:07:30.33,0:07:31.83,Default,,0000,0000,0000,,you can still have\Nthe same element.
Dialogue: 0,0:07:31.83,0:07:33.28,Default,,0000,0000,0000,,The protons can't change.
Dialogue: 0,0:07:33.28,0:07:36.48,Default,,0000,0000,0000,,You change the protons, you've\Ngot a different element.
Dialogue: 0,0:07:36.48,0:07:41.30,Default,,0000,0000,0000,,So let me draw a carbon-12\Nnucleus, one, two, three, four,
Dialogue: 0,0:07:41.30,0:07:43.30,Default,,0000,0000,0000,,five, six.
Dialogue: 0,0:07:43.30,0:07:46.45,Default,,0000,0000,0000,,So this right here is\Nthe nucleus of carbon-12.
Dialogue: 0,0:07:46.45,0:07:48.91,Default,,0000,0000,0000,,And sometimes, it'll\Nbe written like this.
Dialogue: 0,0:07:48.91,0:07:52.72,Default,,0000,0000,0000,,And sometimes, they'll actually\Nwrite the number of protons,
Dialogue: 0,0:07:52.72,0:07:53.84,Default,,0000,0000,0000,,as well.
Dialogue: 0,0:07:53.84,0:07:56.51,Default,,0000,0000,0000,,And the reason why we\Nwrite it carbon-12--
Dialogue: 0,0:07:56.51,0:07:58.83,Default,,0000,0000,0000,,you know, I counted\Nout six neutrons--
Dialogue: 0,0:07:58.83,0:08:00.76,Default,,0000,0000,0000,,is that, this is\Nthe total, you could
Dialogue: 0,0:08:00.76,0:08:04.21,Default,,0000,0000,0000,,view this as the total number\Nof-- one way to view it.
Dialogue: 0,0:08:04.21,0:08:05.58,Default,,0000,0000,0000,,And we'll get a\Nlittle bit nuance
Dialogue: 0,0:08:05.58,0:08:08.37,Default,,0000,0000,0000,,in the future-- is that this\Nis the total number of protons
Dialogue: 0,0:08:08.37,0:08:11.87,Default,,0000,0000,0000,,and neutrons inside\Nof its nucleus.
Dialogue: 0,0:08:11.87,0:08:15.17,Default,,0000,0000,0000,,And this carbon, by definition,\Nhas an atomic number of six,
Dialogue: 0,0:08:15.17,0:08:16.63,Default,,0000,0000,0000,,but we can rewrite\Nit here, just so
Dialogue: 0,0:08:16.63,0:08:18.87,Default,,0000,0000,0000,,that we can remind ourselves.
Dialogue: 0,0:08:18.87,0:08:21.55,Default,,0000,0000,0000,,So at the center of a carbon\Natom, we have this nucleus.
Dialogue: 0,0:08:21.55,0:08:25.00,Default,,0000,0000,0000,,And carbon-12 will have six\Nprotons and six neutrons.
Dialogue: 0,0:08:25.00,0:08:26.97,Default,,0000,0000,0000,,Another version of\Ncarbon, carbon-14,
Dialogue: 0,0:08:26.97,0:08:29.04,Default,,0000,0000,0000,,will still have six\Nprotons, but then it
Dialogue: 0,0:08:29.04,0:08:31.02,Default,,0000,0000,0000,,would have eight neutrons.
Dialogue: 0,0:08:31.02,0:08:32.56,Default,,0000,0000,0000,,So the number of\Nneutrons can change.
Dialogue: 0,0:08:32.56,0:08:34.95,Default,,0000,0000,0000,,But this is carbon-12,\Nright over here.
Dialogue: 0,0:08:34.95,0:08:38.99,Default,,0000,0000,0000,,And if carbon-12 is neutral--\Nand I'll give a little nuance
Dialogue: 0,0:08:38.99,0:08:41.42,Default,,0000,0000,0000,,on this word in a second\Nas well-- if it is neutral,
Dialogue: 0,0:08:41.42,0:08:43.89,Default,,0000,0000,0000,,it'll also have six electrons.
Dialogue: 0,0:08:43.89,0:08:47.69,Default,,0000,0000,0000,,So let me draw those six\Nelectrons, one, two, three,
Dialogue: 0,0:08:47.69,0:08:49.91,Default,,0000,0000,0000,,four, five, six.
Dialogue: 0,0:08:49.91,0:08:52.19,Default,,0000,0000,0000,,And one way-- and this is\Nmaybe the first-order way
Dialogue: 0,0:08:52.19,0:08:54.98,Default,,0000,0000,0000,,of thinking about\Nthe relationship
Dialogue: 0,0:08:54.98,0:08:57.38,Default,,0000,0000,0000,,between the electrons\Nand the nucleus--
Dialogue: 0,0:08:57.38,0:09:00.34,Default,,0000,0000,0000,,is that you can imagine the\Nelectrons are, kind of, moving
Dialogue: 0,0:09:00.34,0:09:02.93,Default,,0000,0000,0000,,around, buzzing\Naround this nucleus.
Dialogue: 0,0:09:02.93,0:09:04.54,Default,,0000,0000,0000,,One model is, you\Ncould, kind of,
Dialogue: 0,0:09:04.54,0:09:06.79,Default,,0000,0000,0000,,thinking of them as\Norbiting around the nucleus.
Dialogue: 0,0:09:06.79,0:09:08.05,Default,,0000,0000,0000,,But that's not quite right.
Dialogue: 0,0:09:08.05,0:09:10.46,Default,,0000,0000,0000,,They don't orbit the\Nway that a planet, say,
Dialogue: 0,0:09:10.46,0:09:11.71,Default,,0000,0000,0000,,orbits around the sun.
Dialogue: 0,0:09:11.71,0:09:13.90,Default,,0000,0000,0000,,But that's a good\Nstarting point.
Dialogue: 0,0:09:13.90,0:09:16.43,Default,,0000,0000,0000,,Another way is, they're kind\Nof jumping around the nucleus,
Dialogue: 0,0:09:16.43,0:09:18.68,Default,,0000,0000,0000,,or they're buzzing\Naround the nucleus.
Dialogue: 0,0:09:18.68,0:09:20.68,Default,,0000,0000,0000,,And that's just\Nbecause reality just
Dialogue: 0,0:09:20.68,0:09:22.10,Default,,0000,0000,0000,,gets very strange at this level.
Dialogue: 0,0:09:22.10,0:09:24.18,Default,,0000,0000,0000,,And we'll actually have\Nto go into quantum physics
Dialogue: 0,0:09:24.18,0:09:26.57,Default,,0000,0000,0000,,to really understand what\Nthe electron is doing.
Dialogue: 0,0:09:26.57,0:09:29.32,Default,,0000,0000,0000,,But a first mental\Nmodel in your head
Dialogue: 0,0:09:29.32,0:09:32.74,Default,,0000,0000,0000,,is at the center of this\Natom, this carbon-12 atom,
Dialogue: 0,0:09:32.74,0:09:37.00,Default,,0000,0000,0000,,you have this nucleus,\Nright over there.
Dialogue: 0,0:09:37.00,0:09:40.70,Default,,0000,0000,0000,,And these electrons are\Njumping around this nucleus.
Dialogue: 0,0:09:40.70,0:09:43.85,Default,,0000,0000,0000,,And the reason why these\Nelectrons don't just
Dialogue: 0,0:09:43.85,0:09:45.36,Default,,0000,0000,0000,,go off, away from this nucleus.
Dialogue: 0,0:09:45.36,0:09:47.57,Default,,0000,0000,0000,,Why they're kind of\Nbound to this nucleus,
Dialogue: 0,0:09:47.57,0:09:49.86,Default,,0000,0000,0000,,and they form part\Nof this atom, is
Dialogue: 0,0:09:49.86,0:09:54.57,Default,,0000,0000,0000,,that protons have\Na positive charge
Dialogue: 0,0:09:54.57,0:09:57.99,Default,,0000,0000,0000,,and electrons have\Na negative charge.
Dialogue: 0,0:09:57.99,0:10:01.87,Default,,0000,0000,0000,,And it's one of these properties\Nof these fundamental particles.
Dialogue: 0,0:10:01.87,0:10:03.29,Default,,0000,0000,0000,,And when you start\Nthinking about,
Dialogue: 0,0:10:03.29,0:10:04.69,Default,,0000,0000,0000,,well, what is a\Ncharge, fundamentally,
Dialogue: 0,0:10:04.69,0:10:05.48,Default,,0000,0000,0000,,other than a label?
Dialogue: 0,0:10:05.48,0:10:07.02,Default,,0000,0000,0000,,And it starts to\Nget kind of deep.
Dialogue: 0,0:10:07.02,0:10:08.81,Default,,0000,0000,0000,,But the one thing\Nthat we know, when
Dialogue: 0,0:10:08.81,0:10:10.67,Default,,0000,0000,0000,,we talk about\Nelectromagnetic force,
Dialogue: 0,0:10:10.67,0:10:13.28,Default,,0000,0000,0000,,is that unlike charges\Nattract each other.
Dialogue: 0,0:10:13.28,0:10:14.89,Default,,0000,0000,0000,,So the best way\Nto think about it
Dialogue: 0,0:10:14.89,0:10:17.10,Default,,0000,0000,0000,,is, protons and\Nelectrons, because they
Dialogue: 0,0:10:17.10,0:10:19.99,Default,,0000,0000,0000,,have different charges,\Nthey attract each other.
Dialogue: 0,0:10:19.99,0:10:21.52,Default,,0000,0000,0000,,Neutrons are neutral.
Dialogue: 0,0:10:21.52,0:10:25.07,Default,,0000,0000,0000,,So they're really just sitting\Nhere inside of the nucleus.
Dialogue: 0,0:10:25.07,0:10:30.70,Default,,0000,0000,0000,,And they do affect the\Nproperties, on some level,
Dialogue: 0,0:10:30.70,0:10:33.33,Default,,0000,0000,0000,,for some atoms of\Ncertain elements.
Dialogue: 0,0:10:33.33,0:10:36.34,Default,,0000,0000,0000,,But the reason why we have the\Nelectrons not just flying off
Dialogue: 0,0:10:36.34,0:10:37.97,Default,,0000,0000,0000,,on their own is\Nbecause, they are
Dialogue: 0,0:10:37.97,0:10:42.47,Default,,0000,0000,0000,,attracted towards the nucleus.
Dialogue: 0,0:10:42.47,0:10:45.69,Default,,0000,0000,0000,,And they also have an\Nunbelievably high velocity.
Dialogue: 0,0:10:45.69,0:10:48.63,Default,,0000,0000,0000,,It's actually hard for-- and\Nwe start touching, once again,
Dialogue: 0,0:10:48.63,0:10:51.26,Default,,0000,0000,0000,,on a very strange\Npart of physics
Dialogue: 0,0:10:51.26,0:10:54.38,Default,,0000,0000,0000,,once we start talking about what\Nan electron actually is doing.
Dialogue: 0,0:10:54.38,0:10:56.78,Default,,0000,0000,0000,,But it has enough, I\Nguess you could say,
Dialogue: 0,0:10:56.78,0:10:59.69,Default,,0000,0000,0000,,it's jumping around enough that\Nit doesn't want to just fall
Dialogue: 0,0:10:59.69,0:11:04.52,Default,,0000,0000,0000,,into the nucleus, I guess is\None way of thinking about it.
Dialogue: 0,0:11:04.52,0:11:08.22,Default,,0000,0000,0000,,And so I mentioned,\Ncarbon-12 right over here,
Dialogue: 0,0:11:08.22,0:11:09.82,Default,,0000,0000,0000,,defined by the\Nnumber of protons.
Dialogue: 0,0:11:09.82,0:11:12.71,Default,,0000,0000,0000,,Oxygen would be defined\Nby having eight protons.
Dialogue: 0,0:11:12.71,0:11:16.42,Default,,0000,0000,0000,,But once again, electrons can\Ninteract with other electrons.
Dialogue: 0,0:11:16.42,0:11:19.14,Default,,0000,0000,0000,,Or they can be taken\Naway by other atoms.
Dialogue: 0,0:11:19.14,0:11:23.38,Default,,0000,0000,0000,,And that actually forms a lot of\Nour understanding of chemistry.
Dialogue: 0,0:11:23.38,0:11:26.40,Default,,0000,0000,0000,,It's based on how many\Nelectrons an atom has,
Dialogue: 0,0:11:26.40,0:11:27.86,Default,,0000,0000,0000,,or a certain element has.
Dialogue: 0,0:11:27.86,0:11:29.58,Default,,0000,0000,0000,,And how those electrons\Nare configured.
Dialogue: 0,0:11:29.58,0:11:33.99,Default,,0000,0000,0000,,And how the electrons of\Nother elements are configured.
Dialogue: 0,0:11:33.99,0:11:36.49,Default,,0000,0000,0000,,Or maybe, other atoms\Nof that same element.
Dialogue: 0,0:11:36.49,0:11:41.18,Default,,0000,0000,0000,,We can start to predict\Nhow an atom of one element
Dialogue: 0,0:11:41.18,0:11:43.36,Default,,0000,0000,0000,,could react with another\Natom of that same element.
Dialogue: 0,0:11:43.36,0:11:46.70,Default,,0000,0000,0000,,Or an atom of one element,\Nhow it could react,
Dialogue: 0,0:11:46.70,0:11:48.78,Default,,0000,0000,0000,,or how it could\Nbond, or not bond,
Dialogue: 0,0:11:48.78,0:11:51.37,Default,,0000,0000,0000,,or be attracted, or\Nrepel, another atom
Dialogue: 0,0:11:51.37,0:11:52.63,Default,,0000,0000,0000,,of another element.
Dialogue: 0,0:11:52.63,0:11:55.23,Default,,0000,0000,0000,,So for example-- and we'll\Nlearn a lot more about this
Dialogue: 0,0:11:55.23,0:12:00.11,Default,,0000,0000,0000,,in the future-- it is possible\Nfor another atom, someplace,
Dialogue: 0,0:12:00.11,0:12:03.18,Default,,0000,0000,0000,,to swipe away an\Nelectron from a carbon,
Dialogue: 0,0:12:03.18,0:12:05.84,Default,,0000,0000,0000,,just because, for\Nwhatever reason.
Dialogue: 0,0:12:05.84,0:12:09.78,Default,,0000,0000,0000,,And we'll talk about certain\Nelements, certain neutral atoms
Dialogue: 0,0:12:09.78,0:12:12.36,Default,,0000,0000,0000,,of certain elements,\Nhave a larger
Dialogue: 0,0:12:12.36,0:12:14.01,Default,,0000,0000,0000,,affinity for\Nelectrons than others.
Dialogue: 0,0:12:14.01,0:12:17.14,Default,,0000,0000,0000,,So maybe one of those swipes\Nan electron away from a carbon,
Dialogue: 0,0:12:17.14,0:12:19.54,Default,,0000,0000,0000,,and then this carbon\Nwill be having
Dialogue: 0,0:12:19.54,0:12:21.73,Default,,0000,0000,0000,,less electrons than protons.
Dialogue: 0,0:12:21.73,0:12:25.37,Default,,0000,0000,0000,,So then it would have five\Nelectrons and six protons.
Dialogue: 0,0:12:25.37,0:12:28.15,Default,,0000,0000,0000,,And then it would have\Na net positive charge.
Dialogue: 0,0:12:28.15,0:12:30.11,Default,,0000,0000,0000,,So, in this carbon-12,\Nthe first version I did,
Dialogue: 0,0:12:30.11,0:12:33.17,Default,,0000,0000,0000,,I had six protons,\Nsix electrons.
Dialogue: 0,0:12:33.17,0:12:34.53,Default,,0000,0000,0000,,The charges canceled out.
Dialogue: 0,0:12:34.53,0:12:37.17,Default,,0000,0000,0000,,If I lose an electron, then\NI only have five of these.
Dialogue: 0,0:12:37.17,0:12:39.21,Default,,0000,0000,0000,,And then I would have\Na net positive charge.
Dialogue: 0,0:12:39.21,0:12:41.24,Default,,0000,0000,0000,,And we're going to talk\Na lot more about all
Dialogue: 0,0:12:41.24,0:12:42.99,Default,,0000,0000,0000,,of this throughout the\Nchemistry playlist.
Dialogue: 0,0:12:42.99,0:12:44.20,Default,,0000,0000,0000,,But hopefully, you\Nhave an appreciation
Dialogue: 0,0:12:44.20,0:12:46.24,Default,,0000,0000,0000,,that this is already\Nstarting to get really cool.
Dialogue: 0,0:12:46.24,0:12:48.30,Default,,0000,0000,0000,,Once we can already\Nget to this really,
Dialogue: 0,0:12:48.30,0:12:52.94,Default,,0000,0000,0000,,fundamental building\Nblock, called the atom.
Dialogue: 0,0:12:52.94,0:12:55.52,Default,,0000,0000,0000,,And what's even neater is that\Nthis fundamental building block
Dialogue: 0,0:12:55.52,0:12:58.80,Default,,0000,0000,0000,,is built of even more\Nfundamental building blocks.
Dialogue: 0,0:12:58.80,0:13:00.63,Default,,0000,0000,0000,,And these things\Ncan all be swapped
Dialogue: 0,0:13:00.63,0:13:03.16,Default,,0000,0000,0000,,around, to change the\Nproperties of an atom,
Dialogue: 0,0:13:03.16,0:13:05.88,Default,,0000,0000,0000,,or to even go from an\Natom of one element
Dialogue: 0,0:13:05.88,0:13:08.47,Default,,0000,0000,0000,,to an atom of another element.