Is helium a diatonic molecule

Answer 1

It's easiest to remember the acronym HOFBrINCl (pronounced "hoffbrinkle") when you're memorizing diatomic molecules. Just remember that each element's symbol is included in the acronym, not just the first letter of the element's name.

Hydrogen

Oxygen

Fluorine

Bromine

Iodine

Nitrogen

ChLorine

or use:

Never - Nitrogen

Have - Hydrogen

Fear - Fluorine

Of - Oxygen

Ice - Iodine

Cold - Chlorine

Beer - Bromine

Helium isn't part of this list, so no, it is not diatomic. It is definitely too inert to regularly form diatomic molecules with itself, although someone managed to make it bond with itself at very, very low temperatures. Even then, the two atoms were separated by an entire arm's length...

Blurb on "diatomic" He: http://www.aip.org/pnu/1993/split/pnu118-2.htm

Hope this helps!

Answer 2

No, helium is a monatomic gas, meaning each helium atom exists as a single atom rather than bonding with other atoms to form molecules.