00:01
In question a, we have to find what is the electronic configuration of the fluorine that has an atomic number of 9 and of the chlorine that has an atomic number of 17.
00:10
Here on the left, i have drawn the order according to which we should allocate electrons to atoms.
00:18
So let's do it for these two electrons.
00:21
First, for the fluorine, we have nine electrons to allocate.
00:27
So the first two go to the 1s sub -shell, then 2 to the 2 to the 2 -s, and 6 to the, actually, and only 5 to the 2 -p to the sub -shell.
00:44
Notice that this amounts to 9 electrons.
00:50
And for the chlorine, we have 1s2, 2 -s2, 2 -p6.
01:01
We have 10 electrons here and we have 7 ago...