WEBVTT 00:00:00.650 --> 00:00:02.420 In the last few videos we learned that 00:00:02.440 --> 00:00:05.300 the configuration of electrons in an atom 00:00:05.340 --> 00:00:08.090 aren't in a simple, classical, 00:00:08.170 --> 00:00:10.460 Newtonian orbit configuration. 00:00:10.500 --> 00:00:12.210 And that's the Bohr model of the electron. 00:00:12.220 --> 00:00:13.840 And I'll keep reviewing it, 00:00:13.890 --> 00:00:14.870 just because I think it's an important point. 00:00:14.890 --> 00:00:16.040 If that's the nucleus, remember, 00:00:16.050 --> 00:00:17.800 it's just a tiny, tiny, tiny dot 00:00:17.820 --> 00:00:21.460 if you think about the entire volume of the actual atom. 00:00:21.570 --> 00:00:24.590 And instead of the electron being in orbits around it, 00:00:24.610 --> 00:00:29.100 which would be how a planet orbits the sun. 00:00:29.110 --> 00:00:30.990 Instead of being in orbits around it, 00:00:31.030 --> 00:00:33.470 it's described by orbitals, 00:00:33.480 --> 00:00:36.570 which are these probability density functions. 00:00:36.590 --> 00:00:39.750 So an orbital-- let's say that's the nucleus 00:00:39.770 --> 00:00:42.170 it would describe, 00:00:42.190 --> 00:00:45.490 if you took any point in space around the nucleus, 00:00:45.500 --> 00:00:48.410 the probability of finding the electron. 00:00:48.420 --> 00:00:53.790 So actually, in any volume of space around the nucleus, 00:00:53.810 --> 00:00:54.780 it would tell you the probability 00:00:54.790 --> 00:00:56.930 of finding the electron within that volume. 00:00:56.950 --> 00:00:58.760 And so if you were to just take 00:00:58.770 --> 00:01:00.370 a bunch of snapshots of electrons 00:01:00.380 --> 00:01:03.160 -- let's say in the 1s orbital. 00:01:03.170 --> 00:01:05.430 And that's what the 1s orbital looks like. 00:01:05.450 --> 00:01:08.510 You can barely see it there, 00:01:08.520 --> 00:01:10.970 but it's a sphere around the nucleus, 00:01:10.990 --> 00:01:14.110 and that's the lowest energy state that an electron can be in. 00:01:14.120 --> 00:01:16.710 If you were to just take a number of snapshots of electrons. 00:01:16.730 --> 00:01:21.370 Let's say you were to take a number of snapshots of helium, 00:01:21.380 --> 00:01:22.700 which has two electrons. 00:01:22.720 --> 00:01:25.760 Both of them are in the 1s orbital. 00:01:25.780 --> 00:01:26.770 It would look like this. 00:01:26.800 --> 00:01:28.470 If you took one snapshot, maybe it'll be there, 00:01:28.480 --> 00:01:30.490 the next snapshot, maybe the electron is there. 00:01:30.530 --> 00:01:32.310 Then the electron is there. 00:01:32.330 --> 00:01:34.120 Then the electron is there. Then it's there. 00:01:34.140 --> 00:01:35.320 And if you kept doing the snapshots, 00:01:35.370 --> 00:01:37.960 you would have a bunch of them really close. 00:01:37.970 --> 00:01:40.940 And then it gets a little bit sparser as you get out, 00:01:40.960 --> 00:01:44.940 as you get further and further out away from the electron. 00:01:44.990 --> 00:01:47.190 But as you see, you're much more likely 00:01:47.210 --> 00:01:50.680 to find the electron close to 00:01:50.700 --> 00:01:54.580 the center of the atom than further out. 00:01:54.630 --> 00:01:56.150 Although you might have had an observation with the electron 00:01:56.170 --> 00:01:58.660 sitting all the way out there, or sitting over here. 00:01:58.680 --> 00:01:59.810 So it really could have been anywhere, 00:01:59.830 --> 00:02:01.490 but if you take multiple observations, 00:02:01.510 --> 00:02:04.910 you'll see what that probability function is describing. 00:02:04.920 --> 00:02:07.250 It's saying look, there's a much lower probability of 00:02:07.270 --> 00:02:11.740 finding the electron out in this little cube of volume space 00:02:11.760 --> 00:02:14.930 than it is in this little cube of volume space. 00:02:14.950 --> 00:02:16.660 And when you see these diagrams 00:02:16.670 --> 00:02:18.620 that draw this orbital like this. 00:02:18.640 --> 00:02:23.820 Let's say they draw it like a shell, like a sphere. 00:02:23.830 --> 00:02:25.590 And I'll try to make it look three-dimensional. 00:02:25.600 --> 00:02:27.290 So let's say this is the outside of it, 00:02:27.310 --> 00:02:29.980 and the nucleus is sitting some place on the inside. 00:02:29.990 --> 00:02:32.760 They're just saying -- they just draw a cut-off 00:02:32.780 --> 00:02:35.010 -- where can I find the electron 90% of the time? 00:02:35.020 --> 00:02:36.240 So they're saying, OK, I can find the electron 00:02:36.260 --> 00:02:38.970 90% of the time within this circle, 00:02:38.990 --> 00:02:40.700 if I were to do the cross-section. 00:02:40.710 --> 00:02:42.200 But every now and then the electron 00:02:42.210 --> 00:02:44.070 can show up outside of that, right? 00:02:44.090 --> 00:02:45.040 Because it's all probabilistic. 00:02:45.060 --> 00:02:46.370 So this can still happen. 00:02:46.390 --> 00:02:47.720 You can still find the electron 00:02:47.740 --> 00:02:51.120 if this is the orbital we're talking about out here. 00:02:51.140 --> 00:02:52.270 Right? 00:02:52.290 --> 00:02:54.180 And then we, in the last video, we said, 00:02:54.200 --> 00:02:57.030 OK, the electrons fill up the orbitals 00:02:57.050 --> 00:03:05.950 from lowest energy state to high energy state. 00:03:05.970 --> 00:03:09.530 You could imagine it. If I'm playing Tetris-- 00:03:09.540 --> 00:03:10.930 well I don't know if Tetris is the thing-- 00:03:10.950 --> 00:03:14.450 but if I'm stacking cubes, I lay out cubes from low energy, 00:03:14.470 --> 00:03:15.440 if this is the floor, 00:03:15.460 --> 00:03:17.720 I put the first cube at the lowest energy state. 00:03:17.730 --> 00:03:21.000 And let's say I could put the second cube 00:03:21.020 --> 00:03:21.930 at a low energy state here. 00:03:21.950 --> 00:03:27.630 But I only have this much space to work with. 00:03:27.650 --> 00:03:28.750 So I have to put the third cube 00:03:28.770 --> 00:03:30.490 at the next highest energy state. 00:03:30.510 --> 00:03:32.030 In this case our energy would 00:03:32.050 --> 00:03:33.980 be described as potential energy, right? 00:03:34.000 --> 00:03:36.350 This is just a classical, Newtonian physics example. 00:03:36.370 --> 00:03:39.540 But that's the same idea with electrons. 00:03:39.560 --> 00:03:44.460 Once I have two electrons in this 1s orbital 00:03:44.470 --> 00:03:49.390 -- so let's say the electron configuration of helium is 1s2 00:03:49.410 --> 00:03:52.390 -- the third electron I can't put there anymore, 00:03:52.400 --> 00:03:54.190 because there's only room for two electrons. 00:03:54.210 --> 00:03:57.270 The way I think about it is these two electrons are now 00:03:57.290 --> 00:03:59.000 going to repel the third one I want to add. 00:03:59.020 --> 00:04:02.410 So then I have to go to the 2s orbital. 00:04:02.420 --> 00:04:06.020 And now if I were to plot the 2s orbital on top of this one, 00:04:06.030 --> 00:04:07.350 it would look something like this, 00:04:07.360 --> 00:04:08.560 where I have a high probability 00:04:08.580 --> 00:04:12.010 of finding the electrons in this shell 00:04:12.030 --> 00:04:19.050 that's essentially around the 1s orbital, right? 00:04:19.070 --> 00:04:23.230 So right now, if maybe I'm dealing with lithium right now. 00:04:23.250 --> 00:04:24.650 So I only have one extra electron. 00:04:24.660 --> 00:04:25.960 So this one extra electron, 00:04:25.970 --> 00:04:29.250 that might be where I observed that extra electron. 00:04:29.270 --> 00:04:30.980 But every now and then it could show up there, 00:04:31.000 --> 00:04:32.840 it could show up there, it could show up there, 00:04:32.860 --> 00:04:34.320 but the high probability is there. 00:04:34.340 --> 00:04:37.110 So when you say where is it going to be 90% of the time? 00:04:37.130 --> 00:04:39.730 It'll be like this shell that's around the center. 00:04:39.750 --> 00:04:40.820 Remember, when it's three-dimensional 00:04:40.840 --> 00:04:42.060 you would kind of cover it up. 00:04:42.080 --> 00:04:42.910 So it would be this shell. 00:04:42.950 --> 00:04:45.170 So that's what they drew here. 00:04:45.180 --> 00:04:47.880 They do the 1s. 00:04:47.900 --> 00:04:49.060 It's just a red shell. 00:04:49.080 --> 00:04:50.490 And then the 2s. 00:04:50.510 --> 00:04:53.580 The second energy shell is just this blue shell over it. 00:04:53.600 --> 00:04:55.630 And you can see it a little bit better in, actually, 00:04:55.650 --> 00:04:57.900 the higher energy orbits, the higher energy shells, 00:04:57.920 --> 00:05:02.280 where the seventh s energy shell is this red area. 00:05:02.290 --> 00:05:04.490 Then you have the blue area, then the red, and the blue. 00:05:04.500 --> 00:05:05.900 And so I think you get the idea 00:05:05.910 --> 00:05:07.370 that each of those are energy shells. 00:05:07.390 --> 00:05:09.100 So you kind of keep overlaying 00:05:09.120 --> 00:05:11.040 the s energy orbitals around each other. 00:05:11.690 --> 00:05:14.360 But you probably see this other stuff here. 00:05:14.380 --> 00:05:15.830 And the general principle, remember, 00:05:15.850 --> 00:05:18.660 is that the electrons fill up the orbital 00:05:18.680 --> 00:05:21.300 from lowest energy orbital to higher energy orbital. 00:05:21.310 --> 00:05:24.920 So the first one that's filled up is the 1s. 00:05:24.940 --> 00:05:26.570 This is the 1. 00:05:26.590 --> 00:05:27.400 This is the s. 00:05:27.410 --> 00:05:28.530 So this is the 1s. 00:05:28.550 --> 00:05:29.980 It can fit two electrons. 00:05:30.000 --> 00:05:32.460 Then the next one that's filled up is 2s. 00:05:32.480 --> 00:05:34.880 It can fill two more electrons. 00:05:34.900 --> 00:05:37.910 And then the next one, and this is where it gets interesting, 00:05:37.920 --> 00:05:40.210 you fill up the 2p orbital. 00:05:40.220 --> 00:05:42.460 2p orbital. 00:05:42.480 --> 00:05:44.180 That's this, right here. 00:05:44.200 --> 00:05:46.870 2p orbitals. 00:05:46.890 --> 00:05:49.420 And notice the p orbitals have something, 00:05:49.440 --> 00:05:53.820 p sub z, p sub x, p sub y. 00:05:53.840 --> 00:05:55.530 What does that mean? 00:05:55.540 --> 00:05:57.250 Well, if you look at the p-orbitals, 00:05:57.270 --> 00:05:58.830 they have these dumbbell shapes. 00:05:58.850 --> 00:06:00.960 They look a little unnatural, but I think in future videos 00:06:00.980 --> 00:06:03.940 we'll show you how they're analogous to standing waves. 00:06:03.960 --> 00:06:06.560 But if you look at these, there's three ways 00:06:06.580 --> 00:06:08.180 that you can configure these dumbbells. 00:06:08.200 --> 00:06:09.850 One in the z direction, up and down. 00:06:09.860 --> 00:06:11.960 One in the x direction, left or right. 00:06:11.980 --> 00:06:13.710 And then one in the y direction, 00:06:13.730 --> 00:06:16.030 this way, forward and backwards, right? 00:06:16.050 --> 00:06:17.650 And so if you were to draw-- 00:06:17.670 --> 00:06:20.600 let's say you wanted to draw the p-orbitals. 00:06:20.620 --> 00:06:22.780 So this is what you fill next. 00:06:22.800 --> 00:06:24.360 And actually, you fill one electron here, 00:06:24.380 --> 00:06:26.530 another electron here, then another electron there. 00:06:26.550 --> 00:06:28.230 Then you fill another electron, 00:06:28.250 --> 00:06:30.110 and we'll talk about spin and things like that in the future. 00:06:30.130 --> 00:06:32.660 But, there, there, and there. 00:06:32.680 --> 00:06:34.110 And that's actually called Hund's rule. 00:06:34.130 --> 00:06:36.150 Maybe I'll do a whole video on Hund's rule, 00:06:36.160 --> 00:06:39.770 but that's not relevant to a first-year chemistry lecture. 00:06:39.790 --> 00:06:42.460 But it fills in that order, and once again, 00:06:42.480 --> 00:06:46.580 I want you to have the intuition of what this would look like. 00:06:46.600 --> 00:06:47.510 Look. 00:06:47.530 --> 00:06:50.140 I should put look in quotation marks, 00:06:50.160 --> 00:06:52.230 because it's very abstract. 00:06:52.240 --> 00:06:54.700 But if you wanted to visualize the p orbitals-- 00:06:54.710 --> 00:06:56.380 let's say we're looking at 00:06:56.390 --> 00:07:00.530 the electron configuration for, let's say, carbon. 00:07:01.840 --> 00:07:04.320 So the electron configuration for carbon, 00:07:04.340 --> 00:07:09.600 the first two electrons go into, so, 1s1, 1s2. 00:07:09.610 --> 00:07:13.650 So then it fills-- sorry, you can't see everything. 00:07:13.670 --> 00:07:18.040 So it fills the 1s2, so carbon's configuration. 00:07:20.170 --> 00:07:23.310 It fills 1s1 then 1s2. 00:07:23.320 --> 00:07:26.530 And this is just the configuration for helium. 00:07:26.550 --> 00:07:28.440 And then it goes to the second shell, 00:07:28.460 --> 00:07:30.970 which is the second period, right? 00:07:30.990 --> 00:07:32.290 That's why it's called the periodic table. 00:07:32.310 --> 00:07:34.520 We'll talk about periods and groups in the future. 00:07:34.540 --> 00:07:35.940 And then you go here. 00:07:35.960 --> 00:07:38.620 So this is filling the 2s. 00:07:38.640 --> 00:07:40.210 We're in the second period right here. 00:07:40.230 --> 00:07:41.960 That's the second period. 00:07:41.980 --> 00:07:43.100 One, two. 00:07:43.120 --> 00:07:45.920 Have to go off, so you can see everything. 00:07:45.940 --> 00:07:47.270 So it fills these two. 00:07:47.290 --> 00:07:50.140 So 2s2. 00:07:50.150 --> 00:07:52.470 And then it starts filling up the p orbitals. 00:07:52.490 --> 00:07:56.320 So then it starts filling 1p and then 2p. 00:07:56.340 --> 00:08:01.720 And we're still on the second shell, so 2s2, 2p2. 00:08:01.740 --> 00:08:04.080 So the question is what would this look like 00:08:04.090 --> 00:08:07.130 if we just wanted to visualize this orbital 00:08:07.150 --> 00:08:08.850 right here, the p orbitals? 00:08:08.870 --> 00:08:11.300 So we have two electrons. 00:08:11.320 --> 00:08:14.610 So one electron is going to be in a-- Let's say if this is, 00:08:14.630 --> 00:08:16.660 I'll try to draw some axes. 00:08:16.680 --> 00:08:18.940 That's too thin. 00:08:20.190 --> 00:08:25.710 So if I draw a three-dimensional volume kind of axes. 00:08:28.430 --> 00:08:30.710 If I were to make a bunch of observations of, say, 00:08:30.720 --> 00:08:33.730 one of the electrons in the p orbitals, 00:08:33.750 --> 00:08:35.600 let's say in the pz dimension, 00:08:35.620 --> 00:08:38.020 sometimes it might be here, sometimes it might be there, 00:08:38.040 --> 00:08:39.020 sometimes it might be there. 00:08:39.040 --> 00:08:45.260 And then if you keep taking a bunch of observations, 00:08:46.510 --> 00:08:51.170 you're going to have something that looks like this bell shape, 00:08:51.190 --> 00:08:53.660 this barbell shape right there. 00:08:53.670 --> 00:08:55.730 And then for the other electron 00:08:55.750 --> 00:08:58.080 that's maybe in the x direction, 00:08:58.100 --> 00:09:00.300 you make a bunch of observations. 00:09:00.320 --> 00:09:01.410 Let me do it in a different, 00:09:01.430 --> 00:09:03.420 in a noticeably different, color. 00:09:03.440 --> 00:09:04.600 It will look like this. 00:09:04.610 --> 00:09:06.740 You take a bunch of observations, and you say, 00:09:06.760 --> 00:09:09.370 wow, it's a lot more likely to find that 00:09:09.390 --> 00:09:12.710 electron in kind of the dumbell, in that dumbbell shape. 00:09:12.730 --> 00:09:13.640 But you could find it out there. 00:09:13.660 --> 00:09:14.550 You could find it there. 00:09:14.570 --> 00:09:15.420 You could find it there. 00:09:15.440 --> 00:09:17.650 This is just a much higher probability of 00:09:17.660 --> 00:09:19.420 finding it in here than out here. 00:09:19.430 --> 00:09:23.520 And that's the best way I can think of to visualize it. 00:09:23.540 --> 00:09:25.220 Now what we were doing here, 00:09:25.230 --> 00:09:27.570 this is called an electron configuration. 00:09:27.590 --> 00:09:30.750 And the way to do it-- and there's multiple ways that are 00:09:30.770 --> 00:09:33.170 taught in chemistry class, but the way I like to do it 00:09:33.190 --> 00:09:40.660 -- is you take the periodic table and you say, these groups, 00:09:40.680 --> 00:09:42.740 and when I say groups I mean the columns, 00:09:42.750 --> 00:09:49.010 these are going to fill the s subshell or the s orbitals. 00:09:51.180 --> 00:09:53.460 You can just write s up here, just right there. 00:09:53.480 --> 00:09:57.930 These over here are going to fill the p orbitals. 00:09:59.630 --> 00:10:01.790 Actually, let me take helium out of the picture. 00:10:01.810 --> 00:10:03.190 The p orbitals. 00:10:03.210 --> 00:10:04.010 Let me just do that. 00:10:04.030 --> 00:10:05.900 Let me take helium out of the picture. 00:10:05.920 --> 00:10:07.580 These take the p orbitals. 00:10:07.600 --> 00:10:09.670 And actually, for the sake of figuring out these, 00:10:09.690 --> 00:10:12.380 you should take helium and throw it right over there. 00:10:12.390 --> 00:10:13.230 Right? 00:10:13.250 --> 00:10:14.610 The periodic table is just a way 00:10:14.630 --> 00:10:16.510 to organize things so it makes sense, 00:10:16.520 --> 00:10:18.420 but in terms of trying to figure out orbitals, 00:10:18.440 --> 00:10:19.900 you could take helium. 00:10:19.910 --> 00:10:20.900 Let me do that. 00:10:20.920 --> 00:10:22.920 The magic of computers. 00:10:22.940 --> 00:10:27.740 Cut it out, and then let me paste it right over there. 00:10:27.760 --> 00:10:29.620 Right? 00:10:29.640 --> 00:10:33.270 And now you see that helium, you get 1s and then you get 2s, 00:10:33.280 --> 00:10:34.690 so helium's configuration is 00:10:34.700 --> 00:10:38.150 -- Sorry, you get 1s1, then 1s2. 00:10:38.160 --> 00:10:40.100 We're in the first energy shell. 00:10:40.110 --> 00:10:41.650 Right? 00:10:41.660 --> 00:10:50.500 So the configuration of hydrogen is 1s1. 00:10:50.520 --> 00:10:52.020 You only have one electron 00:10:52.040 --> 00:10:57.680 in the s subshell of the first energy shell. 00:10:58.260 --> 00:11:01.490 The configuration of helium is 1s2. 00:11:02.280 --> 00:11:06.300 And then you start filling the second energy shell. 00:11:06.320 --> 00:11:12.200 The configuration of lithium is 1s2. 00:11:12.220 --> 00:11:13.580 That's where the first two electrons go. 00:11:13.590 --> 00:11:18.140 And then the third one goes into 2s1, right? 00:11:18.160 --> 00:11:20.570 And then I think you start to see the pattern. 00:11:20.590 --> 00:11:24.330 And then when you go to nitrogen you say, 00:11:24.350 --> 00:11:29.170 OK, it has three in the p sub-orbital. 00:11:29.190 --> 00:11:31.510 So you can almost start backwards, right? 00:11:31.530 --> 00:11:36.230 So we're in period two, right? 00:11:36.240 --> 00:11:38.870 So this is 2p3. 00:11:39.630 --> 00:11:40.510 Let me write that down. 00:11:40.530 --> 00:11:44.300 So I could write that down first. 2p3. 00:11:45.020 --> 00:11:47.720 So that's where the last three electrons 00:11:47.740 --> 00:11:48.930 go into the p orbital. 00:11:48.940 --> 00:11:57.860 Then it'll have these two that go into the 2s2 orbital. 00:11:57.870 --> 00:12:01.390 And then the first two, or the electrons 00:12:01.410 --> 00:12:06.130 in the lowest energy state, will be 1s2. 00:12:06.150 --> 00:12:07.890 So this is the electron configuration, 00:12:07.910 --> 00:12:10.730 right here, of nitrogen. 00:12:11.810 --> 00:12:15.160 And just to make sure you did your configuration right, 00:12:15.180 --> 00:12:17.180 what you do is you count the number of electrons. 00:12:17.200 --> 00:12:20.120 So 2 plus 2 is 4 plus 3 is 7. 00:12:20.130 --> 00:12:22.350 And we're talking about neutral atoms, 00:12:22.370 --> 00:12:24.920 so the electrons should equal the number of protons. 00:12:24.940 --> 00:12:27.440 The atomic number is the number of protons. 00:12:27.450 --> 00:12:28.460 So we're good. 00:12:28.470 --> 00:12:30.590 Seven protons. So this is, so far, 00:12:30.610 --> 00:12:32.620 when we're dealing just with the s's and the p's, 00:12:32.630 --> 00:12:33.980 this is pretty straightforward. 00:12:34.000 --> 00:12:38.310 And if I wanted to figure out the configuration of silicon, 00:12:39.970 --> 00:12:42.010 right there, what is it? 00:12:42.030 --> 00:12:43.840 Well, we're in the third period. 00:12:43.850 --> 00:12:46.070 One, two, three. 00:12:46.090 --> 00:12:47.670 That's just the third row. 00:12:47.690 --> 00:12:50.090 And this is the p-block right here. 00:12:50.110 --> 00:12:52.750 So this is the second row in the p-block, right? 00:12:52.770 --> 00:12:54.940 One, two, three, four, five, six. 00:12:54.960 --> 00:12:56.170 Right. 00:12:56.190 --> 00:12:57.370 We're in the second row of the p-block, 00:12:57.390 --> 00:13:03.080 so we start off with 3p2. 00:13:03.980 --> 00:13:08.310 And then we have 3s2. 00:13:08.330 --> 00:13:10.840 And then it filled up all of this p-block over here. 00:13:10.850 --> 00:13:14.470 So it's 2p6. 00:13:14.490 --> 00:13:16.980 And then here, 2s2. 00:13:17.000 --> 00:13:19.330 And then, of course, it filled up at the first shell 00:13:19.340 --> 00:13:20.870 before it could fill up these other shells. 00:13:20.890 --> 00:13:21.960 So, 1s2. 00:13:21.980 --> 00:13:26.660 So this is the electron configuration for silicon. 00:13:26.670 --> 00:13:29.550 And we can confirm that we should have 14 electrons. 00:13:29.570 --> 00:13:33.280 2 plus 2 is 4, plus 6 is 10. 00:13:33.970 --> 00:13:38.010 10 plus 2 is 12 plus 2 more is 14. 00:13:38.030 --> 00:13:40.020 So we're good with silicon. 00:13:40.040 --> 00:13:42.390 I think I'm running low on time right now, 00:13:42.410 --> 00:13:44.690 so in the next video we'll start addressing what happens 00:13:44.700 --> 00:13:47.840 when you go to these elements, or the d-block. 00:13:47.850 --> 00:13:50.140 And you can kind of already guess what happens. 00:13:50.160 --> 00:13:54.950 We're going to start filling up these d orbitals here 00:13:54.970 --> 00:13:56.540 that have even more bizarre shapes. 00:13:56.550 --> 00:13:59.270 And the way I think about this, not to waste too much time, 00:13:59.290 --> 00:14:03.920 is that as you go further and further out from the nucleus, 00:14:03.940 --> 00:14:06.780 there's more space in between the lower energy orbitals 00:14:06.800 --> 00:14:10.170 to fill in more of these bizarro-shaped orbitals. 00:14:10.190 --> 00:14:12.800 But these are kind of the balance -- 00:14:12.820 --> 00:14:14.830 I will talk about standing waves in the future 00:14:14.840 --> 00:14:16.740 -- but these are kind of a balance between trying to 00:14:16.760 --> 00:14:18.690 get close to the nucleus 00:14:18.710 --> 00:14:20.360 and the proton and those positive charges, 00:14:20.370 --> 00:14:22.310 because the electron charges are attracted to them, 00:14:22.320 --> 00:14:25.250 while at the same time avoiding the other electron charges, 00:14:25.270 --> 00:14:27.820 or at least their mass distribution functions. 00:14:27.840 --> 00:14:29.250 Anyway, see you in the next video.