I'm digging back a ways here, so not sure if this is completely correct.....
Valence shell refers to the electron orbitals an element has. If you look at the Periodic Table, all the elements in any column in the table have similar outer electron orbitals and so all of the elements in that column tend to form molecules of the same sort. For example NaCl (salt) and KCl, where sodium and potasium both form the same sort of molecular bond with chlorine.
If the valence shell is full, then the element is inert like noble gases. Atoms will try to gain or lose electrons to have a full valence shell
Valence cells are those cells that have 8 electrons on their outermost cells
8
It has 6 electrons in it's valance shell and needs 2 more electrons in it's valance shell to become stable. Some atoms, phosphorous for instance ( valance # 5 ), can reach deeper into their valance shell and make additional covalent bonds.
A filled orbital has either 2 electrons (if it is the first shell of an atom) or 8 electrons. This is the highest number of electrons these shell can hold Every orbital tends to complete itself to form a stable element. A filled orbital could be any orbital, either 1st, 2nd, second last or last shell of the atom. An unfilled orbital always has atleast one less electron than the shell can hold. It is always the last shell of an atom and always makes the atom unstable as atom tends to acquire inertness by trying to get this unfilled oribital filled.
Eight - it has a full outer shell of electrons.
It will gain an electron so that it can complete a full outer shell of 8 electrons.
A noble gas is usually unreactive and has a filled valance electron shell. They are located in group 18 on the periodic table.
K shell.
A full octet, valance shell. A valance shell with eight electrons, such as the Nobel gases have, doe not need to donate or accept electrons into or out of the valance shell to be stable.
1
outermost
The valance shell is important in chemical reactions, as it is the valance electrons which are gained/lost during reactions. An atoms valance electron configuration is what largely determines its chemical reactivity.
"valance shell"
It has 6 electrons in it's valance shell and needs 2 more electrons in it's valance shell to become stable. Some atoms, phosphorous for instance ( valance # 5 ), can reach deeper into their valance shell and make additional covalent bonds.
It's valance shell does not contain an octet of eight valance electrons. That simple.
8 valance electrons in valance shell means that atom is stable.
8
1
There is one electron in sodium's valance shell.