[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.35,0:00:02.93,Default,,0000,0000,0000,,- [Instructor] So let's talk\Na little bit about groups
Dialogue: 0,0:00:02.93,0:00:05.89,Default,,0000,0000,0000,,of the periodic table.
Dialogue: 0,0:00:05.89,0:00:08.55,Default,,0000,0000,0000,,Now, a very simple way\Nto think about groups
Dialogue: 0,0:00:08.55,0:00:12.21,Default,,0000,0000,0000,,is that they just are the\Ncolumns of the periodic table,
Dialogue: 0,0:00:12.21,0:00:14.67,Default,,0000,0000,0000,,and standard convention is to number them.
Dialogue: 0,0:00:14.67,0:00:16.94,Default,,0000,0000,0000,,This is the first column,\Nso that's group one,
Dialogue: 0,0:00:16.94,0:00:20.72,Default,,0000,0000,0000,,second column, third group,\Nfourth, fifth, sixth,
Dialogue: 0,0:00:20.72,0:00:25.72,Default,,0000,0000,0000,,seventh, eighth, group\Nnine, group 10, 11, 12,
Dialogue: 0,0:00:27.86,0:00:32.86,Default,,0000,0000,0000,,13, 14, 15, 16, 17, and 18.
Dialogue: 0,0:00:33.87,0:00:35.40,Default,,0000,0000,0000,,And I know some of\Ny'all might be thinking,
Dialogue: 0,0:00:35.40,0:00:37.46,Default,,0000,0000,0000,,what about these f-block\Nelements over here?
Dialogue: 0,0:00:37.46,0:00:39.40,Default,,0000,0000,0000,,If we were to properly\Ndo the periodic table,
Dialogue: 0,0:00:39.40,0:00:41.00,Default,,0000,0000,0000,,we would shift all of these,
Dialogue: 0,0:00:41.00,0:00:44.35,Default,,0000,0000,0000,,everything from the d-block\Nand p-block rightwards,
Dialogue: 0,0:00:44.35,0:00:48.33,Default,,0000,0000,0000,,and make room for these f-block elements,
Dialogue: 0,0:00:48.33,0:00:50.95,Default,,0000,0000,0000,,but the convention is is\Nthat we don't number them.
Dialogue: 0,0:00:50.95,0:00:53.03,Default,,0000,0000,0000,,But what's interesting, why\Ndo we go through the trouble
Dialogue: 0,0:00:53.03,0:00:55.04,Default,,0000,0000,0000,,about calling one of these columns,
Dialogue: 0,0:00:55.04,0:00:57.96,Default,,0000,0000,0000,,of calling these columns a group?
Dialogue: 0,0:00:57.96,0:01:00.92,Default,,0000,0000,0000,,Well, this is what's interesting\Nabout the periodic table,
Dialogue: 0,0:01:00.92,0:01:03.07,Default,,0000,0000,0000,,is that all of the elements in a column,
Dialogue: 0,0:01:03.07,0:01:05.69,Default,,0000,0000,0000,,for the most part, and\Nthere's tons of exceptions,
Dialogue: 0,0:01:05.69,0:01:08.37,Default,,0000,0000,0000,,but for the most part,\Nthe elements in the column
Dialogue: 0,0:01:08.37,0:01:11.07,Default,,0000,0000,0000,,have very very very similar properties,
Dialogue: 0,0:01:11.07,0:01:13.92,Default,,0000,0000,0000,,and that's because the\Nelements in a column,
Dialogue: 0,0:01:13.92,0:01:15.51,Default,,0000,0000,0000,,or the elements in a group,
Dialogue: 0,0:01:15.51,0:01:18.49,Default,,0000,0000,0000,,tend to have the same number of electrons
Dialogue: 0,0:01:18.49,0:01:19.87,Default,,0000,0000,0000,,in their outermost shell.
Dialogue: 0,0:01:19.87,0:01:22.53,Default,,0000,0000,0000,,They tend to have the same\Nnumber of valence electrons,
Dialogue: 0,0:01:22.53,0:01:25.14,Default,,0000,0000,0000,,and valence electrons and\Nelectrons in the outermost shell,
Dialogue: 0,0:01:25.14,0:01:26.72,Default,,0000,0000,0000,,they tend to coincide, although,
Dialogue: 0,0:01:26.72,0:01:28.21,Default,,0000,0000,0000,,there's a slightly different variation.
Dialogue: 0,0:01:28.21,0:01:30.94,Default,,0000,0000,0000,,The valence electrons,\Nthese are the electrons
Dialogue: 0,0:01:30.94,0:01:32.80,Default,,0000,0000,0000,,that are going to react,
Dialogue: 0,0:01:32.80,0:01:35.69,Default,,0000,0000,0000,,which tend to be the\Noutermost shell electrons,
Dialogue: 0,0:01:35.69,0:01:38.33,Default,,0000,0000,0000,,but there are exceptions to that,
Dialogue: 0,0:01:38.33,0:01:40.93,Default,,0000,0000,0000,,and there's actually a lot\Nof interesting exceptions
Dialogue: 0,0:01:40.93,0:01:43.71,Default,,0000,0000,0000,,that happen in the transition\Nmetals, in the D block,
Dialogue: 0,0:01:43.71,0:01:45.31,Default,,0000,0000,0000,,but we're not gonna go into those details.
Dialogue: 0,0:01:45.31,0:01:46.53,Default,,0000,0000,0000,,Let's just think a little bit about
Dialogue: 0,0:01:46.53,0:01:49.04,Default,,0000,0000,0000,,some of the groups that\Nyou will hear about,
Dialogue: 0,0:01:49.04,0:01:51.86,Default,,0000,0000,0000,,and why they react in very similar ways.
Dialogue: 0,0:01:51.86,0:01:53.84,Default,,0000,0000,0000,,So if we go with group one,
Dialogue: 0,0:01:53.84,0:01:55.36,Default,,0000,0000,0000,,group one, and hydrogen is a little bit
Dialogue: 0,0:01:55.36,0:01:57.26,Default,,0000,0000,0000,,of a strange character,
Dialogue: 0,0:01:57.26,0:01:58.56,Default,,0000,0000,0000,,because hydrogen isn't trying to get
Dialogue: 0,0:01:58.56,0:02:00.11,Default,,0000,0000,0000,,to eight valence electrons,
Dialogue: 0,0:02:00.11,0:02:01.40,Default,,0000,0000,0000,,hydrogen in that first shell
Dialogue: 0,0:02:01.40,0:02:05.23,Default,,0000,0000,0000,,just wants to get to two valence\Nelectrons, like helium has,
Dialogue: 0,0:02:05.23,0:02:06.93,Default,,0000,0000,0000,,and so hydrogen is kind of,
Dialogue: 0,0:02:06.93,0:02:10.35,Default,,0000,0000,0000,,it's not, it doesn't\Nshare as much in common
Dialogue: 0,0:02:10.35,0:02:11.67,Default,,0000,0000,0000,,with everything else in group one
Dialogue: 0,0:02:11.67,0:02:12.91,Default,,0000,0000,0000,,as you might expect for, say,
Dialogue: 0,0:02:12.91,0:02:15.10,Default,,0000,0000,0000,,all of the things in group two.
Dialogue: 0,0:02:15.10,0:02:17.43,Default,,0000,0000,0000,,Group one, if you put hydrogen aside,
Dialogue: 0,0:02:17.43,0:02:21.94,Default,,0000,0000,0000,,these are referred to\Nas the alkali metals,
Dialogue: 0,0:02:21.94,0:02:24.80,Default,,0000,0000,0000,,and hydrogen is not\Nconsidered an alkali metal,
Dialogue: 0,0:02:24.80,0:02:27.42,Default,,0000,0000,0000,,so these right over here are the alkali,
Dialogue: 0,0:02:28.50,0:02:30.10,Default,,0000,0000,0000,,alkali metals.
Dialogue: 0,0:02:31.32,0:02:34.56,Default,,0000,0000,0000,,Now why do all of these\Nhave very similar reactions?
Dialogue: 0,0:02:34.56,0:02:36.75,Default,,0000,0000,0000,,Why do they have very similar properties?
Dialogue: 0,0:02:36.75,0:02:37.72,Default,,0000,0000,0000,,Well, to think about that,
Dialogue: 0,0:02:37.72,0:02:40.50,Default,,0000,0000,0000,,you just have to think about\Ntheir electron configurations.
Dialogue: 0,0:02:40.50,0:02:44.71,Default,,0000,0000,0000,,So, for example, the electron\Nconfiguration for lithium
Dialogue: 0,0:02:44.71,0:02:46.63,Default,,0000,0000,0000,,is going to be the same
Dialogue: 0,0:02:46.63,0:02:51.17,Default,,0000,0000,0000,,as the electron configuration of helium,
Dialogue: 0,0:02:51.17,0:02:53.47,Default,,0000,0000,0000,,of helium, and then,
Dialogue: 0,0:02:53.47,0:02:58.03,Default,,0000,0000,0000,,you're going to go to\Nyour second shell, 2s1.
Dialogue: 0,0:02:58.03,0:02:59.82,Default,,0000,0000,0000,,It has one valence electron.
Dialogue: 0,0:02:59.82,0:03:03.65,Default,,0000,0000,0000,,It has one electron in\Nits outermost shell.
Dialogue: 0,0:03:03.65,0:03:04.99,Default,,0000,0000,0000,,What about sodium?
Dialogue: 0,0:03:06.21,0:03:09.21,Default,,0000,0000,0000,,Well, sodium is going to have the same
Dialogue: 0,0:03:09.21,0:03:12.00,Default,,0000,0000,0000,,electron configuration as neon,
Dialogue: 0,0:03:13.26,0:03:16.20,Default,,0000,0000,0000,,and then it's going to go 3s1,
Dialogue: 0,0:03:16.20,0:03:18.95,Default,,0000,0000,0000,,so once again, it has\None valence electron,
Dialogue: 0,0:03:18.95,0:03:21.24,Default,,0000,0000,0000,,one electron in its outermost shell.
Dialogue: 0,0:03:21.24,0:03:23.78,Default,,0000,0000,0000,,So all of these elements\Nin orange right over here,
Dialogue: 0,0:03:23.78,0:03:25.35,Default,,0000,0000,0000,,they have one valence electron,
Dialogue: 0,0:03:25.35,0:03:27.86,Default,,0000,0000,0000,,and they're trying to\Nget to the octet rule,
Dialogue: 0,0:03:27.86,0:03:30.88,Default,,0000,0000,0000,,this kind of stable nirvana for atoms,
Dialogue: 0,0:03:30.88,0:03:33.22,Default,,0000,0000,0000,,and so you can imagine is\Nthat they're very reactive,
Dialogue: 0,0:03:33.22,0:03:35.19,Default,,0000,0000,0000,,and when they react, they tend to lose
Dialogue: 0,0:03:35.19,0:03:38.45,Default,,0000,0000,0000,,this electron in the outermost\Nshell, and that is the case.
Dialogue: 0,0:03:38.45,0:03:41.86,Default,,0000,0000,0000,,These alkali metals\Nare very very reactive,
Dialogue: 0,0:03:41.86,0:03:43.31,Default,,0000,0000,0000,,and actually, they have\Nvery similar properties.
Dialogue: 0,0:03:43.31,0:03:46.79,Default,,0000,0000,0000,,They're shiny and soft, and actually,
Dialogue: 0,0:03:46.79,0:03:47.96,Default,,0000,0000,0000,,because they're so reactive,
Dialogue: 0,0:03:47.96,0:03:49.60,Default,,0000,0000,0000,,it's hard to find them where they haven't
Dialogue: 0,0:03:49.60,0:03:51.53,Default,,0000,0000,0000,,reacted with other things.
Dialogue: 0,0:03:51.53,0:03:53.96,Default,,0000,0000,0000,,Well, let's keep looking\Nat the other groups.
Dialogue: 0,0:03:53.96,0:03:57.41,Default,,0000,0000,0000,,Well, if we move one over to the right,
Dialogue: 0,0:03:57.41,0:04:00.41,Default,,0000,0000,0000,,this group two right over here,
Dialogue: 0,0:04:00.41,0:04:03.35,Default,,0000,0000,0000,,these are called the\Nalkaline earth metals.
Dialogue: 0,0:04:04.27,0:04:09.27,Default,,0000,0000,0000,,Alkaline, alkaline earth metals.
Dialogue: 0,0:04:09.34,0:04:13.88,Default,,0000,0000,0000,,And once again, they have\Nvery similar properties,
Dialogue: 0,0:04:13.88,0:04:16.38,Default,,0000,0000,0000,,and that's because they\Nhave two valence electrons,
Dialogue: 0,0:04:16.38,0:04:19.35,Default,,0000,0000,0000,,two electrons in their outermost shell,
Dialogue: 0,0:04:19.35,0:04:21.96,Default,,0000,0000,0000,,and also for them, not quite as reactive
Dialogue: 0,0:04:21.96,0:04:23.57,Default,,0000,0000,0000,,as the alkali metals,
Dialogue: 0,0:04:23.57,0:04:27.42,Default,,0000,0000,0000,,but let me write this,\Nalkaline earth metals,
Dialogue: 0,0:04:27.42,0:04:29.64,Default,,0000,0000,0000,,but for them it's easier\Nto lose two electrons
Dialogue: 0,0:04:29.64,0:04:31.86,Default,,0000,0000,0000,,than to try to gain six to get to eight,
Dialogue: 0,0:04:31.86,0:04:34.47,Default,,0000,0000,0000,,and so these tend to also\Nbe reasonably reactive,
Dialogue: 0,0:04:34.47,0:04:38.92,Default,,0000,0000,0000,,and they react by losing\Nthose two outer electrons.
Dialogue: 0,0:04:38.92,0:04:42.71,Default,,0000,0000,0000,,Now something interesting\Nhappens as you go to the D-block,
Dialogue: 0,0:04:42.71,0:04:44.51,Default,,0000,0000,0000,,and we studied this when we looked
Dialogue: 0,0:04:44.51,0:04:46.27,Default,,0000,0000,0000,,at electron configurations,
Dialogue: 0,0:04:46.27,0:04:48.43,Default,,0000,0000,0000,,but if you look at the\Nelectron configuration
Dialogue: 0,0:04:48.43,0:04:51.25,Default,,0000,0000,0000,,for say, scandium right over here,
Dialogue: 0,0:04:51.25,0:04:54.35,Default,,0000,0000,0000,,the electron, let me do it in magenta,
Dialogue: 0,0:04:54.35,0:04:57.42,Default,,0000,0000,0000,,the electron configuration for scandium,
Dialogue: 0,0:04:57.42,0:04:58.82,Default,,0000,0000,0000,,so scandium,
Dialogue: 0,0:05:01.07,0:05:02.43,Default,,0000,0000,0000,,scandium's electron configuration
Dialogue: 0,0:05:02.43,0:05:06.08,Default,,0000,0000,0000,,is going to be the same as argon,
Dialogue: 0,0:05:06.08,0:05:08.17,Default,,0000,0000,0000,,it's going to be argon.
Dialogue: 0,0:05:08.17,0:05:10.30,Default,,0000,0000,0000,,The aufbau principle would tell us
Dialogue: 0,0:05:10.30,0:05:12.15,Default,,0000,0000,0000,,that the electron configuration,
Dialogue: 0,0:05:12.15,0:05:15.86,Default,,0000,0000,0000,,we would have the 4s2 just like calcium,
Dialogue: 0,0:05:15.86,0:05:17.52,Default,,0000,0000,0000,,but by the aufbau principle,
Dialogue: 0,0:05:17.52,0:05:21.40,Default,,0000,0000,0000,,we would also have one electron in 3d.
Dialogue: 0,0:05:21.40,0:05:24.84,Default,,0000,0000,0000,,So it would be argon, then 3d1 4s2.
Dialogue: 0,0:05:27.28,0:05:30.67,Default,,0000,0000,0000,,And to get things in the\Nright order for our shells,
Dialogue: 0,0:05:30.67,0:05:34.51,Default,,0000,0000,0000,,let me put the 3d1 before the 4s2.
Dialogue: 0,0:05:34.51,0:05:37.32,Default,,0000,0000,0000,,And so when people think\Nabout the aufbau principle,
Dialogue: 0,0:05:37.32,0:05:40.30,Default,,0000,0000,0000,,they imagine all of these d-block elements
Dialogue: 0,0:05:40.30,0:05:43.00,Default,,0000,0000,0000,,as somehow filling the d-block.
Dialogue: 0,0:05:43.00,0:05:45.98,Default,,0000,0000,0000,,Now as we know in other videos,\Nthat's not exactly true,
Dialogue: 0,0:05:45.98,0:05:49.34,Default,,0000,0000,0000,,but when you're conceptualizing\Nthe electron configuration
Dialogue: 0,0:05:49.34,0:05:51.27,Default,,0000,0000,0000,,it might be useful.
Dialogue: 0,0:05:51.27,0:05:54.60,Default,,0000,0000,0000,,Then you come over here and\Nyou start filling the p-block.
Dialogue: 0,0:05:54.60,0:05:59.24,Default,,0000,0000,0000,,So for example, if you look\Nat the electron configuration
Dialogue: 0,0:05:59.24,0:06:01.81,Default,,0000,0000,0000,,for, let's say carbon,
Dialogue: 0,0:06:01.81,0:06:05.93,Default,,0000,0000,0000,,carbon is going to have the\Nsame electron configuration
Dialogue: 0,0:06:05.93,0:06:09.41,Default,,0000,0000,0000,,as helium, as helium,
Dialogue: 0,0:06:09.41,0:06:12.45,Default,,0000,0000,0000,,and then you're going to\Nfill your s-block 2s2,
Dialogue: 0,0:06:12.45,0:06:13.50,Default,,0000,0000,0000,,and then 2p one 2.
Dialogue: 0,0:06:15.70,0:06:17.59,Default,,0000,0000,0000,,So 2p2.
Dialogue: 0,0:06:17.59,0:06:19.60,Default,,0000,0000,0000,,So how many valence\Nelectrons does it have?
Dialogue: 0,0:06:19.60,0:06:21.70,Default,,0000,0000,0000,,Well, in its second shell,\Nits outermost shell,
Dialogue: 0,0:06:21.70,0:06:24.89,Default,,0000,0000,0000,,it has two plus two, it\Nhas four valence electrons,
Dialogue: 0,0:06:24.89,0:06:28.18,Default,,0000,0000,0000,,and that's going to be true\Nfor the things in this group,
Dialogue: 0,0:06:28.18,0:06:29.34,Default,,0000,0000,0000,,and because of that,
Dialogue: 0,0:06:29.34,0:06:34.12,Default,,0000,0000,0000,,carbon has similar bonding\Nbehavior to silicon,
Dialogue: 0,0:06:34.12,0:06:36.12,Default,,0000,0000,0000,,to the other things in its group.
Dialogue: 0,0:06:36.12,0:06:38.63,Default,,0000,0000,0000,,And we can keep going on, you know,
Dialogue: 0,0:06:38.63,0:06:42.73,Default,,0000,0000,0000,,for example, oxygen, oxygen and sulfur,
Dialogue: 0,0:06:42.73,0:06:45.84,Default,,0000,0000,0000,,these would both want\Nto take two electrons
Dialogue: 0,0:06:45.84,0:06:48.62,Default,,0000,0000,0000,,from someone else because they\Nhave six valence electrons,
Dialogue: 0,0:06:48.62,0:06:49.55,Default,,0000,0000,0000,,they want to get to eight,
Dialogue: 0,0:06:49.55,0:06:51.58,Default,,0000,0000,0000,,so they have similar bonding behavior.
Dialogue: 0,0:06:51.58,0:06:53.44,Default,,0000,0000,0000,,You go to this yellow\Ngroup right over here,
Dialogue: 0,0:06:53.44,0:06:55.49,Default,,0000,0000,0000,,these are the halogens.
Dialogue: 0,0:06:55.49,0:06:57.10,Default,,0000,0000,0000,,So there's a special name for them.
Dialogue: 0,0:06:57.10,0:06:59.65,Default,,0000,0000,0000,,These are the halogens.
Dialogue: 0,0:06:59.65,0:07:01.25,Default,,0000,0000,0000,,And these are highly reactive,
Dialogue: 0,0:07:01.25,0:07:03.03,Default,,0000,0000,0000,,because they have seven valence electrons.
Dialogue: 0,0:07:03.03,0:07:03.96,Default,,0000,0000,0000,,They would love nothing more
Dialogue: 0,0:07:03.96,0:07:06.25,Default,,0000,0000,0000,,than to get one more valence electron,
Dialogue: 0,0:07:06.25,0:07:07.61,Default,,0000,0000,0000,,so they love to react, in fact,
Dialogue: 0,0:07:07.61,0:07:09.08,Default,,0000,0000,0000,,they especially love to react
Dialogue: 0,0:07:09.08,0:07:11.85,Default,,0000,0000,0000,,with the alkali metals over here.
Dialogue: 0,0:07:11.85,0:07:16.15,Default,,0000,0000,0000,,And then finally, you get to\Nkind of your atomic nirvana
Dialogue: 0,0:07:16.15,0:07:18.52,Default,,0000,0000,0000,,in the noble gases here.
Dialogue: 0,0:07:18.52,0:07:20.90,Default,,0000,0000,0000,,And so the noble gases,\Nthat's the other name
Dialogue: 0,0:07:20.90,0:07:25.90,Default,,0000,0000,0000,,for the group 18 elements, noble gases.
Dialogue: 0,0:07:26.03,0:07:28.56,Default,,0000,0000,0000,,And they all have the\Nvery similar property
Dialogue: 0,0:07:28.56,0:07:29.71,Default,,0000,0000,0000,,of not being reactive.
Dialogue: 0,0:07:29.71,0:07:30.74,Default,,0000,0000,0000,,Why don't they react?
Dialogue: 0,0:07:30.74,0:07:32.60,Default,,0000,0000,0000,,They have filled their outermost shell.
Dialogue: 0,0:07:32.60,0:07:34.22,Default,,0000,0000,0000,,They don't find the need, they're noble,
Dialogue: 0,0:07:34.22,0:07:35.56,Default,,0000,0000,0000,,they're kind of above the fray,
Dialogue: 0,0:07:35.56,0:07:40.51,Default,,0000,0000,0000,,they don't find the need to\Nhave to react with anyone else.