chlorine, flourine, helium, nitrogen
please explain
2007-04-04 06:50:18 · 5 answers · asked by BOO 1 in Science & Mathematics ➔ Chemistry
Helium is a monoatomic gas at STP.
"Monoatomic" means the gas exists as individual atoms, not molecules.
STP = standard temperature and pressure that is equal to 1 atmosphere of pressure at 32 degrees F.
There are seven elements that bond to themselves in the gas phase, and thereby create "diatomic" gases:
hydrogen H2
nitrogen N2
oxygen O2
fluorine F2
chlorine Cl2
bromine Br2
Iodine I2
Although bromine is a liquid at STP, and iodine a solid, they both evaporate easily and create noticable vapors that you can see rise up that are the diatomic gas.
The most unreactive elements are the noble gases (helium, neon, argon, krypton, xenon). They are unreactive and have little or no tendency to accept or give up electrons.
The halogens (F, Cl, Br, I) are one electron short of a noble gas, and are searching for that one electron in every chemical reaction they undergo.
If there are no other elements present, the halogens will bond and share two electrons between them (single bond). Each atom of the pair is then as close to a noble gas as it is going to get.
Oxygen is two electrons short of a noble gas, and will share four electrons between two oxygen atoms (double bond).
Nitrogen is three electrons short of a noble gas, and will share six electrons between two nitrogen atoms (triple bond).
Hydrogen is one electron short of a noble gas, and will share two electrons between two hydrogen atoms (single bond).
2007-04-04 07:24:19 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Helium. It is a noble gas. It already has the exact amount of electrons (2) in it's shell/orbital that it needs. No more. No less.
All of those others need some electrons in their outer shells/orbitals so they need to share some with another atom (of chlorine, florine, or nitrogen)
.
2007-04-04 06:55:45 · answer #2 · answered by tlbs101 7 · 0⤊ 0⤋
Helium, as a noble gas it does not need a partner to fill it's (already full) octet structure. This is actually true for the whole homologous series: Helium, Neon, Argon, Krypton, Xenon, Radon.
2007-04-04 06:54:09 · answer #3 · answered by Anonymous · 0⤊ 0⤋
helium
because it has completed its set of electrons(2 for the first orbit)
2007-04-04 06:54:30 · answer #4 · answered by diwa 1 · 0⤊ 0⤋
i think the answer is Helium. are you from rotter's chemistry class? hahah
2007-04-07 11:37:42 · answer #5 · answered by treehugger 1 · 0⤊ 0⤋