Can someone please explain the Octet rule to me?

Answer 1

Any atom in main group chemistry can only have a maximum of 8 electrons in its valence orbital (outter shell).

elements want to have this magic number of 8 electrons in there outter shell. For example the formation of NaCL. Sodium (Na) has 1 electron in its outter oribital, chlorine (CL) has 7 electrons in its outter shell. Therefore Na and CL want to form an ionic compund so they both have 8 electrons in there outter shell.

Covalent compounds work in a similar way, except There will be transfer of electrons rather than electron sharing.

The reason its 8 is because of the S and P orbitals. there can be a maximum of 2 in the S orbital and 6 in the P orbital.

This is an over simplification though as there are orbitals which can hold more than 8 electronsd and f orbitals in the transition metals), but its the basic idea you are taught at your level of chemistry ^^

Answer 2

Ok. It's like this.

All of the Elements want to be happy, and they can only be happy by filling their "outer orbital" by having a certain number of valence electrons; the electrons on the outmost shell of the atom.

Now here are the shell numbers and max. number of e- (electrons) allowed in each
:
1st 2nd 3rd 4th
-2- - 8- -8- -2- (in grade 9 anyways)

Take Mg (Magnesium). It has 3 shells, one with 2 e-, another with 8 e-, and the last, outer orbital has 2e- for a toal of 12 e-.

It wants to lose those 2 e-, to make 2 shells. one with 2e-, and the- other with 8e-. the second shell, which has 8e-, is said to be stable and therefore have a "stable octet" (oct- eight! see?)

One element that Mg could give it's electrons away to, to become happy, would be Oxygen, which has 6 valance electrons. 6 e- on the outer shell.

When they combine, they make MgO. The Mg gives it's two electrons to the Oxygen and they form an Ionic Compound. MgO is also a nice compound used in products like Tums and Gaviscon.

Also, some elemets like Argon, Neon, and Helium are called "Noble Gases" because they do not need another set of electrons, they already got 8e- on the outer shell.

Answer 3

The rule is that for an atom to be stable, at least in most cases, they want 8 valence electrons. And the valence electrons are what determines how a certain element bond chemically.