Gravity is not "a wave" but there do seem to be gravitational waves. The particle associated with gravitation is called the graviton.

Originally Posted by
Humanfit
Does it change depending on what kind of matter is amassed?
What type of change are you talking about? What do you mean by "kind of matter"?

Originally Posted by
Humanfit
Also wouldn't the lighter elements be weaker against the force of gravity?
Lighter elements have less mass and are therefore less gravity, if that's what you're asking. They are not "weaker against the force of gravity".

Originally Posted by
Humanfit
Why is it that lighter elements go away from earth then?
Im not sure what youre asking.