The molecules of a substance are moving rapidly in a container. the molecules do not interact with each other. if the container is opened, the molecules will escape from the container. in what phase of matter are the molecules in the container?
a) plasma
b) gas correct answer
c) liquid
d) solid

The answer is: gas
- First, we have to understand the 4 state of matter:
1) Solids: The molecular or ionic attracts each other by intermolecular forces. They connect with each other by strong convalent bonds that are hard to be broken in normal conditions. The heat energy is used to go through the weak intermolecular forces, So in a normal case, the solids usually have a stable shape.

2) Liquid: Unlike gases, It will take the container shape, and haven't the ability to change its volume to fill a container  The intermolecular bonding is helping to give liquid its certain volume. Liquid able to flow and take any shape according to the container shape. The molecules of the liquid are closed together that is why it is hard to compress, the only high pressure will be able to compress it a little.

3)Gases:  gases move rapidly in a straight line until it hit an object like the wall of the container then start to move with an aimless direction in a random way called random walk and unlike liquids, it can be compressed.

4) plasma: is unlike the gases, liquid and solid. It does not exist normally on the earth but we have to generate it from neutral gases.It has a neutral charge.

The answer is c. 320 g