Two bottles of gases are sitting on a shelf at 25c. bottle a contains hydrogen gas and bottle b contains helium gas.
a) in which bottle do the molecules of gas have the higher average kinetic energy?
b) in which bottle are the molecules moving faster (have a higher average velocity)?
c) if not the same velocity, by how much faster is the velocity of the gases?

Substance x has a fixed volume, and the attraction between its particles is strong .substance y had widely spread out particles and can be compressed what can most likely be concluded about these substances

Compare and contrast physical changes with chemical changes.

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size