How does particle theory explain density

Iron in the liquid state occupies a greater volume than the same mass of iron in the solid state. Iron atoms are further apart in liquid iron. A substance evaporates or boils when it changes from the liquid state to the gas state. Its particles move so there is a large change in volume and density. Calculate the mass of oxygen that occupies 0. Oxygen in the gas state has a much smaller mass than the same volume of oxygen in the liquid state. Oxygen molecules are much further apart in gaseous oxygen, so they occupy a much larger volume.

Solids, liquids and gases All matter consists of particles including atoms and molecules. The arrangement and movement of these particles differ between the different states of matter: solids - particles are close together in a regular structure and vibrate about fixed positions liquids - particles are close together but free to move past each other randomly gases - particles are far apart and move randomly in all directions The density of a substance changes when it changes state.

Solids and liquids A substance melts when it changes from the solid state to the liquid state. Liquids and gases A substance evaporates or boils when it changes from the liquid state to the gas state. Particle theory helps to explain properties and behaviour of materials by providing a model which enables us to visualise what is happening on a very small scale inside those materials.

As a model it is useful because it appears to explain many phenomena but as with all models it does have limitations. Why do you think that the same volume of different materials have differing masses E. Website maintainer: R. Jones Updated: November 13,