Which of the following statements is true about gasses?

1)density cannot be determined for a gas.
2)the volume of a gas is always equal to the volume of the enclosing container.
3)the density of a gas equals volume per unit mass.
4)a balloon containing a gas with greater density than air will rise.

i think it is 2 but i'm not sure

2)The volume of a gas is always equal to the volume of the enclosing container.

Explanation:

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.