[tamubsa]

Why does Ne have a lower boiling point than CH4? Since they both only have dispersion forces, shouldn't the one with the lower molar mass have the lower boiling point? I'm a little confused. Thanks in advance!

[Kate]

I don't know, but maybe because Ne is a noble gas and atoms of Ne don't form covalent bonds between themselves.

[Corribus]

Why does Ne have a lower boiling point than CH4? Since they both only have dispersion forces, ...

Not all dispersion forces are created equal. Mass is often used as a surrogate for size, which is the more important consideration.  Neon may weigh more, but methane is bigger.  It's electrons are more diffuse, it is more polarizeable, and hence the magnitude of its dispersion forces are larger.  It is more sticky as a result, and thus takes more energy to boil.

That's my hand-waving argument, anyway.

[tamubsa]

That makes sense. Thank you.

[Kate]

I don't know, but maybe because Ne is a noble gas and atoms of Ne don't form covalent bonds between themselves.

I just realized the stupidity of what I wrote, confusing intermolecular bonds with intramolecular ones.