Summary For States Of Matter

• The 3 main states of matter are liquid , solid and gas.

• The structures of solids, liquids and gases can be described in terms of particle separation, arrangement and motion.

• Different changes in state can take place, including melting and freezing, evaporation and condensation, and boiling.

• Changes of state can be produced by changing conditions of temperature and/or pressure.

• Pure substances have precise melting and boiling points.

• The kinetic particle model describes the idea that the particles of a substance are in constant motion and that the nature and amount of motion of these particles differs in a solid, liquid or gas.

• Changing physical state involves energy being absorbed or given out, the temperature of the substance staying constant while the change takes place (as illustrated by the experimental construction of cooling curves).

• Changes in temperature or the external pressure produce changes in the volumes of gases which can be explained in terms of the kinetic particle theory.

• Diffusion in liquids and gases is the spreading of particles to fill all of the space available.

• The rate of diffusion of a gas is dependent on molecular size, with molecules of lower mass diffusing more quickly than those of higher mass.

Project : The Goldilocks principle

• How we experience the world around us depends upon the physical conditions and states in which substances exist. This is particularly true in the case of water.

• The Earth is the only body in our solar system where water exists in all three states of matter.

Presence of water :

What is distinctive about the physical conditions on Earth that mean that life could begin, and continue to exist, here? Why is water so important when thinking about how life began? Is Earth the only planet to have water and therefore life? Have other planets had water in their past? Recent space probes have been sent to try to find water on Mars and the moons of Jupiter and Saturn.

The Goldilocks Zone

• Earth orbits the Sun at just the right distance for liquid water to exist on its surface. It is neither too hot nor too cold for this. Research this situation, which is known as the Goldilocks Zone.