# Introduction to different types of state of matter

Contributed by:
There are three states of matter: solid; liquid and gas. They have different properties, which can be explained by looking at the arrangement of their particles.
1. background sheet
Three states of matter
There are three states of matter: solid; liquid and gas. They have different
properties, which can be explained by looking at the arrangement of their
SOLIDS LIQUIDS GASES
Solids contain particles arranged Liquids contain particles that roll Gases contain particles that move
in a lattice structure. The particles around each other and settle on around very quickly. The particles
vibrate in their fixed positions. the bottom of their container. travel in straight lines until they
The particles are generally bounce off another particle or a
This explains properties of solids:
slightly further apart than in a surface. Gas particles are widely
• They can’t be compressed solid. (Water is an exception – ice spaced and tend to be only slightly
(particles are already tightly particles are slightly further apart attracted to each other.
packed together). than liquid water, which is why ice
This explains properties of a gas:
• They keep their shape and have floats.)
a constant volume when they • They fill available space (slight
This explains properties of liquids:
change container (particles are in attraction between particles).
fixed positions). • They change shape when poured • They are very compressible
into a different container (particles are widely spaced).
(particles roll over each other and
settle on the bottom).
• They have constant volume
(particles are close together).
• They are slightly compressible.
(There are slight spaces between
particles.)
Absolute zero
This is the theoretical temperature at which particles
have the least amount of energy and the slowest
movement. It occurs at -273.15 °C, or 0 Kelvin on the
scientific temperature scale. Scientists have not been
able to cool down any substance to this temperature
but have come very close. It used to be thought that
particles would stop moving at absolute zero but
experiments have shown that this isn’t the case.
Particles in motion
All particles are constantly in motion. This is called
the kinetic theory of matter. When energy is added to
particles (in the form of heat energy for example) they
move faster. When energy is removed (for example by TERM CHANGE IN STATE
cooling) then the particles move slower.
melt (melting) solid to liquid
Changing state evaporate (evaporation) liquid to gas
condense (condensation) gas to liquid
Adding or removing energy from particles can cause
them to change state. Heating or cooling particles are freeze (freezing) liquid to solid
ways of adding or taking away energy. It causes changes sublime (sublimation) solid to gas
in the arrangement and movement of particles, and
can lead to changes in state. There are names for the deposit (deposition) gas to solid
ast0778 | Soft drink science 3: Three states of matter (background sheet) developed for the Department of Education WA
© The University of Western Australia 2012 for conditions of use see spice.wa.edu.au/usage
version 1.0 page 1 Licensed for NEALS
2. Solutions Supersaturation
A solution forms when a solid (the solute) dissolves A supersaturated solution forms when a solution
in a liquid (the solvent). Although solutions are contains an amount of solute dissolved in the solvent
generally thought of as a solid dissolved in a liquid, that is larger than the amount that is usually able
both solute and solvent can be any phase: solid, liquid to dissolve in a saturated solution. This is tricky to
or gas. In this case the solvent is the phase that occurs achieve and maintain but can be achieved by heating
in the greatest quantity. the solute to a high temperature, adding the solvent
to create a saturated solution, then either cooling the
PHASES EXAMPLE SOLUTION solution; increasing the pressure of the solution; or
solid in liquid seawater removing some of the solvent through evaporation.
Supersaturated solutions are usually very unstable.
liquid in liquid alcohol in cleaners
gas in liquid oxygen in water Separation techniques
gas in gas air
Mixtures and solutions can be separated using
solid in solid metal alloy, steel physical methods.
(carbon in iron)
TECHNIQUE APPLICATION
Suspensions are a type of mixture in which larger
particles are held up or suspended by collisions with chromatography separates substances that have
the molecules of the liquid or gas that contains them. different levels of attraction to
Particles in a suspension will eventually settle. In a a solvent
colloid (such as milk or vinaigrette) the distributed crystallisation separates dissolved solids from
particles are so small that they do not settle. liquids
SUSPENSION COMPONENTS distillation separates liquids dissolved in
liquids
smoke ash suspended in air
evaporation separate liquids from solids
muddy water clay suspended in water that have very high melting
fog water droplets points
suspended in air filtration separates suspended solids in
liquid
Solubility nucleation separates gas from liquids
Solubility is the defined as mass of solute that can
dissolve in a given amount of solvent, at a particular Particles
temperature and pressure.
Particles in states of matter may be in the form of
When particles dissolve in a solvent to form a solution molecules or ions.
they are surrounded by solvent particles, as shown in
the learning object Soft drink science 4: Solutions. A Molecules are particles that are made up of atoms
common misconception is that solute particles wander of one or more elements. They can be made up of
around in the gaps between solvent particles. This is single atoms, for example helium and argon, or many
not the case: there is an interaction between solute atoms like sulfur or carbon. Most molecules contain
and solvent, known as solvation, in which solvent atoms of different elements. For example, a water
molecules form a solvation shell that surrounds molecule contains two hydrogen atoms and one
solvent molecules. If the solvent is water this is known oxygen atom; and glucose contains six carbon atoms,
as a hydration shell. twelve hydrogen atoms and six oxygen atoms in each
molecule.
Solutions have a saturation point. This is the point
when no more solute can dissolve in the solvent and Ions are charged particles that have either gained
the solution becomes a saturated solution. For some or lost electrons. If they have gained electrons they
solutes the saturation point varies widely, depending are negatively-charged particles and if they have
on solvent temperature, for example sugar and water. lost electrons they are positively-charged particles.
However other solutes show only a small increase in In common salt, sodium chloride, each sodium atom
solubility when temperature increases, for example loses one electron to form a sodium ion and chlorine
salt. atoms each gain an electron to form chloride ions.