00:01
Okay, so today we're going to be doing electron configurations specifically for these following ions.
00:10
So starting off, we're going to go with as3 minus.
00:14
So we've got to look for as on our periodic table.
00:20
And we find that it's after argon, so it's after the third period.
00:26
And it is going to be in group 15.
00:30
So since it's after argon, but before krypton, we can start off by putting a bracketed ar here to represent how it's after ar in the periodic table.
00:49
So we don't have to write out everything else before that.
00:52
Next, we have to recognize that we will be on the fourth s orbital.
01:00
And since as falls in the p orbital of this, it has its s orbital.
01:08
So it's going to have a 2 above that, denoting that it's full.
01:14
Next, we have to take into account for the d orbital.
01:18
So we put 3d 10, 3 because it's at a lower energy level than that s.
01:26
But we write it after.
01:29
Next, we, and then finally, we are going to be writing for the p orbitals.
01:33
You have to count how many spaces over as is.
01:36
So we count one, two, three.
01:40
A .s.
01:41
Is after gallium and germanium, uh, within the atomic number of 33.
01:46
And since it's in that group 15, it's going to have a four p three.
02:00
But this would be normal arsenic.
02:03
So we need to erase that three real quick and taking into the fact that there are three extra electrons meaning that the normal where the normal arsenic is you have to move three groups over which is going to put this at the end of the p orbital actually where krypton would normally be so that would be the full electron configuration for arsenic so now let's try and do this one a little bit quicker so we have iodine.
02:36
So it's going to be after going to be in group 17 in period 5.
02:42
So it's going to be after the element krypton and the noble gases.
02:46
So if you said that we can bracket kr here, you're right.
02:51
So you can bracket kr so that we can skip writing everything else before that.
02:57
And then next we can write 4d2.
03:07
So i can write 5s2, 4d10.
03:18
And then since it has one extra electron, it's going to be where xenon normally is in the p -orbital.
03:27
But i just like to write it out just so we know exactly where it is and not just that it's taking up xenon spot instead of just bracketing xenon.
03:37
So it's going to be 5p6, very similar to the last.
03:41
Last one we just did.
03:43
Okay.
03:44
So next we're going to go to b .e.
03:46
Or beryllium with a two plus charge, meaning that it has lost two electrons.
03:54
So perilium is going to be in group two and period two.
04:00
So when you take away two electrons and move two periodic spots to the left, it's actually again, enough where helium is, meaning that the, sorry, the electron configuration for this is simply going to be 1s.
04:23
That's a pretty simple one.
04:24
Next, we have cd.
04:28
Let's make that a little bit near for you guys.
04:31
And where is cd in the periodic table? so, cd is going to be in just add it.
04:47
Give me one second.
04:49
It's going to be after krypton, so it's going to be in the fifth period.
04:54
And it's going to be in group 12.
04:58
So we're not even going to get to the p orbitals for this one.
05:04
And we can also skip, so we can skip the p orbitals.
05:17
We can't skip the s orbitals here...