43 a sample of helium gas is in a sealed, rigid container. what occurs as the temperature of the sample is increased? (1) the mass of the sample decreases.
(2) the number of moles of gas increases.
(3) the volume of each atom decreases.
(4) the frequency of collisions between atoms increases.

What is a main difference between a mixture and a pure substance? a mixture is only a liquid, but a pure substance can be in any state.a mixture looks the same throughout, but a pure substance does not.1 a mixture can vary in composition, but a pure substance has a set composlo a mixture can be made up of a single compound, but a pure substance car