Answer:
It corresponds to Charles' Law
Explanation:
Charles's Law corresponds to one of the gas laws, where temperature and volume are related, to constant pressure. That is, according to said equation, the volume of a gas varies directly with the temperature, under conditions of constant pressure.
Magnet to remove the iron, filter paper (or some filter that could trap sand) to remove the sand, and heat up the salt and water, causing the water to evaporate to separate them.
Based on the Zeroth Law of Thermodynamics, two systems are at equilibrium when there is no heat flow, q, between the systems.
The state of the substance, most likely, would be a gas. Given the same amount of the substance being able to fill different volumes of containers, means that the substance is compressible. From the three phases of matter, gas is surely the compressible one while liquids are sometimes compressible but only up to certain extent. Also, the substance cannot be a a solid since a solid would have a definite shape and volume. Nor it cannot be a liquid since a liquid cannot fill the whole container and it does not change its volume no matter what is the container.
