This page relates to the physical factors affecting chemical processes..
States of matter
Matter exists mainly in three states gas, liquid and solid. A material
such as water can exist as a gas (steam) a liquid (water) or a solid (ice). Its state
results from its condition of temperature and pressure.
A gas has no bounding surface it fills all of the space it occupies. Its density is very much
related to the quantity of matter the temperature and the pressure.
A liquid has no shape. It takes the shape of the vessel it occupies. It does however
have a surface which limits the volume it occupies. It is normally has a greater density than a gas.
Its volume and related density is affected to some extent by temperature and to a lesser effect
by pressure. Liquids are often assumed to be incompressible
A solid has a fixed shape and its volume changes by only a relative small amount
on changes of pressure and temperature.
In normal conditions a solid can be converted to a liquid if its temperature is
raised to its melting point temperature and a liquid can be converted to a gas
if its temperature is raised to its evaporation tempature which is related to
the local pressure..