Question

Two basic properties of the gas phase are

Answer 1

They have a very low density

They fill the container they are in

Step-by-step explanation:

The first main characteristic is that they have a very low density, which is logical considering that gasses are lighter than the other states of matter (solid and liquid), however some gasses are extremely light, and some very heavy (by the relative measurement of other gasses). For example Helium is lighter than Nitrogen, so therefore we will breathe in more nitrogen than helium.

The majority of gasses are restricted to the "container" of our atmosphere, which explains why gasses never stay still, they are all trying to spread out evenly around the planet.

Answer 2

The choices can be found elsewhere and as follows:

A.) a definite shape and a definite volume
B.) a definite shape but no definite volume
C.) no definite shape and no definite volume

I believe the correct answer is option C. Two basic properties of the gas phase would be it has no definite shape and no definite volume. It takes the shape and volume of its container. Hope this answers the question.