00:01
All right.
00:02
This question takes a look at writing electron configurations for species.
00:06
And of course, we need to utilize the periodic table to be able to help us with this process.
00:12
So the first example we're going to take a look at, ask specifically for a group five element and ask for the third element in that group.
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So that's going to be arsenic right here.
00:25
And so we're going to use the longhand configuration for this one.
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And then we'll take a look at the shorthand configuration.
00:33
Option or alternate when we're done with this.
00:36
So we start with the very first row of the periodic table and have the first two electrons contained in that 1s subshell.
00:45
So here we go, 1s2, then we move to the second row of the periodic table.
00:53
Two more s electrons now in the 2s sub shell.
00:56
And we start utilizing the 2p sub shell in that second row of the periodic table and there are going to be six electrons.
01:03
That go into that 2p subshell.
01:05
So the next step in the process then is, repeat the pattern, go to the third row of the periodic table and utilize the 3s subshell there and the 3p subshell.
01:21
So 3s2, 3p6.
01:23
But we know arsenics in the fourth row, so we have to keep going to the process.
01:29
4s sub shell is going to contain the first two electrons, but now we also start utilizing the d sub shell in the center of the table and it's the 3d sub shell that we start using.
01:42
And it's going to contain 10 more electrons to find a home for.
01:47
So the 3d 10 subshell gets us up to this point in the process.
01:52
And now we move back to the fourth shell and start utilizing that four p sub shell.
02:01
Three more electrons to find a home for to get us up to arsenic 4p3.
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And that's the longhand electron configuration.
02:11
An alternate that we can use that's a lot faster and easier is to find the nearest noble gas to whatever element that we're going to do an electron configuration for, but it has to come before that element.
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So the nearest noble gas that comes before arsenic is argon.
02:29
We contain all of the core electrons in the argon symbol.
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And then we move to the next row of the periodic table to start taking a look at those valence or higher energy electrons.
02:43
So from argon, now we can do the first two 4s electrons, the 3d10 electrons, and the 4p3 electrons.
02:55
And this is the shorthand configuration, and it sure does come in handy for a lot of examples, especially, the next example we're going to do.
03:06
This is element number 16.
03:12
So this is livermoryum.
03:14
That name just flows off the tongue, doesn't it? it's element number 116, and as you can see, it's way down in row seven of the periodic table.
03:22
So this would be like we wouldn't have enough paper essentially to do the longhand version.
03:28
So let's use a much shorter version.
03:30
Let's find the nearest noble gas that comes before livermoryum in the periodic table...
