Download States of Matter - GaryTurnerScience

States of Matter
Matter
Everything around us is made up of
matter.
Matter can be weighed, and this is called
its mass.
Matter takes up space - the amount of
space occupied by something is called its
volume.
So matter is anything that takes up space,
and can be weighed. That is… has a mass
and a volume.
The Particle Model
All matter is made up of invisible particles.
Particles have kinetic energy and are constantly
moving
Spaces exist between particles
As temperature increases, the kinetic energy of
particles increases.
Particles are attracted to each other by forces of
attraction. The strength of these forces, along
with the temperature determine the state of the
matter (solid, liquid, gas)
States of Matter
Matter can be classified into three main
groups: solids, liquids and gases.
These are called the three states of
matter.
Solids
Solids include such things as your desk, and most
objects around you. They occupy space and can be
weighed.
The volume of a solid cannot easily be changed, nor can
the shape.
Substances will be solids because
either:
• The attractive forces between
them are strong enough to hold
them tightly; or
• The temperature is low and the
particles have very little kinetic
energy – easily held tightly
together even by weak attractive
forces (is frozen)
Liquids
Water, milk and oil are examples of matter in liquid form.
The volume of a quantity of liquid does not change, but
its shape may.
The molecules are not as close together as they were in
the solid and the particles can move around slightly.
Substances will be liquids because
either:
• The attractive forces between them
are not strong enough to hold them
tightly, but still hold them together;
or
• The temperature is high and the
particles have too much kinetic
energy to be held tightly, but not
enough to separate completely
Gases
As the temperature increases the liquid changes to a
gas. The attractive forces between molecules are very
weak and the particles are therefore not held together.
The particles are very far apart.
Substances will be gases because
either:
• The attractive forces between them
are very weak and not strong
enough to hold the particles
together; or
• The temperature is very high and
the particles have too much kinetic
energy to be held together, even by
strong attractive forces.
Changes in State
When a liquid is heated and turns into a gas it is
said to have evaporated 9or vapourised).
When a gas cools and turns into a liquid it is said
to have condensed.
Freezing is when a liquid turns into a solid.
Melting is when a solid turns into a liquid.
Boiling is when the vapour pressure of a liquid is
equal to the external air pressure (chem defn) – or it
is rapid evaporation