7. there is 17 electrons, 2 in the first shell, 8 in the second and 7 in the third
There is one electron in sodium's valance shell.
1
14
There are two electrons in the valance shell of helium. Since this is the first shell, it is filled by two electrons.
Eight - it has a full outer shell of electrons.
1
3 valance electrons,13 electrons,13 protons,14 neutrons
Protons won't be found in an electron shell. They are concentrated in the nucleus.
There are 9 protons in the element fluorine.
There are three valance electrons. These are the electrons in the outer shell if it is not full.
Group I A elements have 1 valance electron.
Hydrogen has one shell with only 1 electron on the valance shell.