00:02
Hi there.
00:03
In this question, we want to know which of these ions has a noble gas electron configuration.
00:09
So first of all, i want to identify where the noble gases are on the periodic table.
00:15
The noble gases are group 8a.
00:21
So this last group on the periodic table are the noble gases.
00:24
So we want to know which of these ions has the same configuration as a noble gas.
00:30
In other words, to have the same configuration, it must be isoelectronic.
00:37
In other words, it must have the same number of electrons.
00:43
So same configuration equals isoelectronic.
00:52
So we are looking for which of these ions has the same number of electrons as a noble gas.
00:58
And as we're talking about ions, there are two types of ions.
01:03
There are cat ions, which are positive ions.
01:07
And they are formed by losing one or more electrons.
01:18
And anions are negative ions.
01:23
They are formed by gaining one or more electrons.
01:32
Okay, i think we have the information we need to start looking at our answer choices.
01:36
Our first answer choice is aluminum with a 4 plus charge.
01:43
Well, aluminum, if we find it here on the periodic table, its atomic number is 13.
01:49
So that means an atom, a neutral atom, would have 13 electrons.
01:56
But this is the ion, and it has a positive charge, a positive 4, so it's a cat ion.
02:02
So that means it has lost four electrons.
02:05
So i need to subtract four electrons from this, giving us nine electrons.
02:11
So this would be isoelectronic with atomic number 9, which is fluorine.
02:19
So this ion does not have the electron configuration of a noble gas.
02:27
Let's move on.
02:28
Let's look at the next one...
