00:02
Hi there.
00:03
In this question, we have a little bit of problem solving to do.
00:07
And several of these tell us that either the anion or the cat ion contains 36 electrons.
00:17
All right.
00:18
So the element that has 36 electrons would be the one that has 36 protons and is krypton.
00:27
So any of these that form ions with 36 electrons will have the same electron configuration.
00:33
And therefore the same number of electrons as krypton.
00:37
Okay, so let's go ahead and get started.
00:39
In letter a, we are told we have a halogen.
00:44
Well, the halogens are in group 7a of the periodic table.
00:50
So these are the halogens here in group 7a.
00:56
So we want the anion that is going to have 36 electrons from group 7a.
01:03
And that appears that it is going to be bromine, because bromine has 35 electrons as an atom, but to get the configuration of a noble gas, it will gain one, making it be an anion with a one -negative charge, and then it will have 36 electrons.
01:23
So the element is bromine, br.
01:31
All right, letter b.
01:33
Letter b, we are looking for a radioactive noble gas with 86 protons.
01:38
Well, the noble gases are found in group 8a, and we're looking for the one that has 86 protons.
01:49
So that is its atomic number.
01:52
The number of protons is the atomic number.
01:55
So our answer here, the one with 86 as its atomic number, is radon.
02:08
All right, so radon, rn is our answer for letter b.
02:14
Let's look at letter c.
02:15
In letter c, we have a group 6a, element.
02:19
All right.
02:19
Well, 6a is the group that starts with oxygen, and its anion contains 36 electrons.
02:27
So anion means it has gained electrons to get the configuration of the closest noble gas.
02:34
So it's going to have the configuration of krypton, but it's in group 6a...