Answer: option container C: the purple dots.
Explanation:
There are four physical states of matter:
1) Gas: in this state the neutral atoms or molecules are separated, moving freely, so that the particles occupy the whole container. The best representation corresponds to the paired green/orange dots in cylinder B: the dots are paired, meaning that they are not free ions, but neutral particles, and they occupy the entire sapece inside the cylinder.
2) Liquid: in this state the molecules are closer than in the solid stated. They yet flow (the molecules or atoms slip respect the others and can pass to each other). There is some attraction between the molecules so they cannot occupy the entire space in the container, but they can adopt the shape of the part where they are. This is perfectrly represented by the purple dots in the cylinder C.
3) Solid: the molecules or ions are tighty packed. They cannot pass each other. They are in fixed position. They vibrate in fixed positions. The substance do not change the form to adapt the container. This is represented by the red dots in cylinder D.
4) Plasma: is a state similar to gas, but the particles are free ions. That is what the blue dots in cylnder A.
