2007-01-28 13:12:39 · 10 answers · asked by ninekittys 3 in Science & Mathematics ➔ Earth Sciences & Geology
They have completely filled their electron orbitals.
What this means is that it takes more energy to either gain or lose electrons than if they just stay the way they are. And if you want to react with other elements the atom must either give or gain electrons or share them. The noble gases don't normally do either.
So they are in a sort of energy well with walls on each side they cannot get over and out of.
With some of the noble gases with greater masses they can be forced into an associated covalent bond with selected other elements but the compounds tend not to be stable and decompose, returning the noble gas compound to being a noble gas unattached atom.
2007-01-28 13:16:31 · answer #1 · answered by Alan Turing 5 · 2⤊ 0⤋
Because they are stable. They have an octet around them - meaning 8 valence electrons causing them to be stable. Most elements are reactive because they dont have a full outer shell of valence electrons around them (8 electrons).
Take carbon for example - it is in column 4 - which also means it has 4 valence electrons (noble gases are in column 8.... ) so carbon needs to share 4 more electrons to be stable and neutral. so a molecule of CH4 is stable because the carbon has its own 4 valence electrons and then is sharing the 1 electron from each of the 4 Hydrogens... therefore it has an octet of 8 electrons surrounding it.
It is the same thing with the noble gases except that they ALREADY have 8 valence electrons and dont have to share.
2007-01-28 21:20:57 · answer #2 · answered by Fox_747 2 · 1⤊ 1⤋
The most stable electron configuration for an atom is to have all of its orbitals filled (or half-filled). Noble gasses have an even 8 valence electrons, filling the outer orbitals. All elements want to be a noble gas. For example, sodium has one extra electron than a full 8 in the outer shell, so it frequently loses that electron to form the sodium ion, Na+, achieving a noble gas configuration.
Basically, noble gasses have the most stable electron configuration (orbitals filled).
2007-01-28 21:16:51 · answer #3 · answered by Intrepyd 5 · 1⤊ 1⤋
Because elements normally react to fill their outer electron shell with 8 electrons. The noble gases have a full outer shell, and thus are highly nonreactive.
2007-01-28 21:18:30 · answer #4 · answered by Steve 1 · 1⤊ 1⤋
A few bad answers here.
Yes they have full electron shells which is the most stable configuration but not every orbital shell is filled up with 8 electrons.
Helium only has 2 - thats all it takes to fill up the innermost electron shell.
2007-01-28 21:33:59 · answer #5 · answered by Anonymous · 0⤊ 0⤋
because it has all the electrons it needs to be neutral
the outermost energy shell of the atom itself is full
it does not want any more and give any thing away because it is all filled up
2007-01-28 22:37:10 · answer #6 · answered by unitedstatesairforce555 2 · 0⤊ 0⤋
Their valence electron level already has 8 electrons--so its full. It doesn't need to gain or lose any electrons because it is already stable, so it just does not react.
2007-01-28 21:19:02 · answer #7 · answered by danamarin 2 · 1⤊ 1⤋
Their outer electron shells are full -- they don't need to share electrons or otherwise interact with other atoms.
2007-01-28 21:16:09 · answer #8 · answered by ecolink 7 · 1⤊ 0⤋
because they have a full outer ring of electrons
2007-01-28 21:17:02 · answer #9 · answered by matthew b 3 · 2⤊ 0⤋
they have 8 valene electrons
2007-01-28 21:16:36 · answer #10 · answered by elibelly 2 · 1⤊ 1⤋