Atoms tend to lose or gain electrons to complete the octet number of electrons in the outermost shell. Why is it to be 8 electrons and not 7 or any other number?
2006-09-06 10:31:29 · 3 answers · asked by Theme 1 in Science & Mathematics ➔ Chemistry
The motion of an electron in relation to the nucleus of an atom is called an orbital and each orbital contains pairs of electrons. The atom is in a lower energy state when 2 electrons occupy an orbital rather than one. That is why atoms with only one electron in an orbital (like sodium) are very reactive.
The "light" elements Li through Ar have electrons in two types of orbital relationships: One "s" orbital and three "p" orbitals (s and p are just lables at this point). If all 4 orbitals are stable with 2 electrons each, (a total of eight electrons) you have an energy favorable state. Thus the octet rule for a stable element/ion.
Note the octet rule is just that, a rule, and rules are made to be broken. Boron can be stable with only 6 electrons (as are Al and Ga), Helium is (extremely) stable with only two electrons.
Enjoy!
2006-09-06 15:51:42 · answer #1 · answered by DrSean 4 · 0⤊ 0⤋
The octet is actually true for the second and third row of elements. The first row only requires two electrons. Beyond the third row, it gets tricky.
What we are really looking for is a completely filled electron shell. Partially filled shells allow reactions to occur -- for the second and third row eight electron fill the shell. It is also possible to lose electrons and revert back to a previously filled shell. Usually atoms from the IA and IIA groups prefer to lose one or two electrons and revert back to the completely filled shell of the previous row.
2006-09-06 17:51:58 · answer #2 · answered by The Q 2 · 0⤊ 0⤋
you've got the answer to you question already
2006-09-06 18:53:51 · answer #3 · answered by topgun 2 · 0⤊ 0⤋