Not necessarily; the range of a paper aircraft can be effected by more than just size, weight and speed.
it is lighter than water.
It is lighter than air.
heavier because they are two different weights
Helium is lighter than air
Methane is lighter than air.
Oxygen is the heavier part, nitrogen and argon are lighter, even water vapor is lighter.
One is lighter and the other one is heavier. :D