Question

A scientist heats a flexible container full of neon gas. What will most likely happen to the container as the gas absorbs heat?

It will shrink, because the neon atoms will break apart into smaller pieces.

It will expand, because the neon atoms will get larger.

It will expand, because the neon atoms will move more quickly and get farther apart.

It will shrink, because the neon atoms will lose energy as heat, and move closer together.

Answer 1

As you heat gas up, the molecules move more rapidly. This pushes harder on the outside of the container, forcing it to expand. Atoms do not change in size. 
So, the answer to the second question is C. It will expand because the neon atoms will move more quickly and get farther apart.

Answer 2

Answer: It will expand, because the neon atoms will move more quickly and get farther apart.

Explanation: This can be explained based on Charle's law.

Charles' Law: This law states that volume is directly proportional to the temperature of the gas at constant pressure and number of moles.

$V\propto T$    (At constant pressure and number of moles)

Thus if a gas absorbs heat at constant pressure and no of moles, the temperature of the gas increases and thus the volume also increases and thus it expands by gaining kinetic energy and moving far apart.