The following image shows what happens when the particles in a certain state occupy a space. What is the state of the substance that is occupying the space and how do you know? (box with atoms scattered in it)

The substance is a gas because the particles are spreading out to fill the space of the container.

The substance is a liquid because the particles inside are taking the shape of the container.

The substance is a mixture of a gas and a liquid because the particles are filling the space of the container.

The substance is a solid because the particles inside the box have a definite shape.