Supercritical Fluid
When a substance expands, its mass remains constant, as mass is a measure of the amount of matter in an object and does not change with volume. However, the density of the substance decreases because density is defined as mass per unit volume. Thus, as the substance expands and its volume increases, the same mass is distributed over a larger volume, resulting in lower density.
It expands to fill the container.
if matter expands to fill the volume of its container its a suspension.
Neither. Volume is independent of mass. Effectively, if you increase the volume of a substance you are moving the particles that comprise that substance apart. Eventually, you would have a gas which expands to fill the volume of its container.
the density decreases because the particles spread out and so less particles occupy the same amount of area meaning the substance is less dense.
When a substance expands, its mass remains constant, as mass is a measure of the amount of matter in an object and does not change with volume. However, the density of the substance decreases because density is defined as mass per unit volume. Thus, as the substance expands and its volume increases, the same mass is distributed over a larger volume, resulting in lower density.
It expands to fill the container.
If the substance takes the shape of its container, has no definite volume, and can be easily compressed, it is likely a gas. Additionally, gases typically exert pressure on the walls of their container and expand to fill the available space.
This would be a gas. A gas expands to fill the space of the container that contains it.
if matter expands to fill the volume of its container its a suspension.
No. A drop of water and a tankerful of it have the same density. But these are two different masses of the same material. If you have, say a piece of metal and heat it up so that it expands, and there is still the same amount of substance, then the density decreases as the substance expands. Water expands as it freezes; that is why ice floats in water.
if matter expands to fill the volume of its container its a suspension.
Neither. Volume is independent of mass. Effectively, if you increase the volume of a substance you are moving the particles that comprise that substance apart. Eventually, you would have a gas which expands to fill the volume of its container.
The density decreases.
water
Think of of the expanding substance as a box full of marbles. If it expands, they end up in a bigger space (in this case a bigger box). Because of that they have more room to move around and there will be less particles and less mass per cm2 which is what the density is.
the air in the container expands