Help? I need to figure out how many electrons are needed to complete the outermost shell?

Chemistry isn't and never will be my thing so I was wondering if anyone could help me with completing the outermost shell of an electron?





I have to figure out how for Fluorine, Hydrogen, Carbon, Nitrogen, Oxygen, Phosphorus, and Sulfur.


I don't need the answers for all of them I would just like an example, please and thank youuuu!Help? I need to figure out how many electrons are needed to complete the outermost shell?
you need either 8 or 2 to get a full valence shell. eg hydrogen has 1 electron so it will gain 1 electron to have a full valence shell. oxygen has 6 electrons, so it needs 2 more electrons to have a full valence shell and so it gains 2 electronsHelp? I need to figure out how many electrons are needed to complete the outermost shell?
An easy hint is to look at the columns (the groups) in a Periodic table. If you ignore the big block in the middle (the transitional elements), you're left with eight groups. The first one, starting with Hydrogen at the top, has one electron in its outer shell. Group 2, starting with Beryllium, has two. Skip the transitionals, and you have group 13, starting with Boron. That has three. (Rule of thumb for these ones - subtract ten, since you skipped ten groups.) And so on, all the way up to the noble gases starting with Helium, group 18, with eight electrons in its outer shell (except for Helium itself, which only has two, but that still fills its outer shell since it only has that one shell).





So let's take Phosphorus. Phosphorus is underneath Nitrogen, which is in group fifteen. Therefore, it has five electrons in its outer shell, and can take in three more.





Hope this helps!