Question

1. a helium balloon rises when its let go. which statement best explains this phenomenon? a. the air is made of gases that are less dense than helium. b. the helium in the balloon is denser than air. c. unseen wind currents carry the balloon upward. d. helium is less dense than the air in the atmosphere.

Explanation:

The principle of buoyancy states that an object will rise in a fluid if its density is less than the density of the fluid. Helium is less dense than air, so a helium - filled balloon rises in the air.

Answer:

d. Helium is less dense than the air in the atmosphere.