What is the primary effect of kinetic energy on the molecules within a substance?

It causes the molecules to stick together more strongly.

It makes the molecules move and spread apart.

It changes the chemical composition of the molecules.

It eliminates the force of attraction between molecules.

Which statement most accurately describes the constant 'competition' within a substance that determines its phase?

Kinetic energy works to separate molecules, while molecular attraction works to pull them together.

Molecular attraction causes molecules to move, while kinetic energy holds them in a fixed position.

Both kinetic energy and molecular attraction work together to cause molecules to spread apart.

The competition is between gravity and kinetic energy, which determines the substance's overall weight.