Describe the structure of solids, liquids and gases in terms of particle separation, arrangement and types of motion State the distinguishing properties of solids, liquids and gases • Describe and explain diffusion (1 core) • Describe evidence for the movement of particles in gases and liquids (1 core) Describe changes of state in terms of melting, boiling, evaporation, freezing, condensation and sublimation Explain changes of state in terms of the kinetictheory

1.  WELCOME TO IGCSE CHEMISTRY
 We will cover the objectives given in Cambridge
syllabus. Every IGCSE syllabus has its own code.
 Chemistry syllabus code is 0620
 You will have three papers when appearing in final
exams for IGCSE (extended)
 Paper 2: MCQs (30% of overall marks)
 Paper 4: written answers (50 % of overall marks)
 Paper 6: alternative to practical. (20% of overall
marks)

4.  Describe the structure of solids, liquids and gases in terms
of particle separation, arrangement and types of motion
 State the distinguishing properties of solids, liquids and
gases
 • Describe and explain diffusion (1 core)
 • Describe evidence for the movement of particles in gases
and liquids (1 core)
 Describe changes of state in terms of melting, boiling,
evaporation, freezing, condensation and sublimation
 Explain changes of state in terms of the kinetic
theory

5.  Matter is defined as anything that has mass and
occupies space/ has some volume.
 Everything is made up of matter. The
characteristics of matter are: Made up of particles –
atoms, molecules or ions
 Particles are in constant motion
 Has a mass
 Has a volume
 EAXMPLES: Air, water, glass, cement, chair, table
and everything around us is made up of matter.

6.  All type of matter is made up of tiny bits called
particles. It is just like a wall made of bricks.
Different arrngemnet, spacing and the movement of
particles makes three different states of matter.
 The differnece in properties of states of matter arise
due to ;
 Particles arrangement: regular or irregular
 Spacing: close/touching each other or far from
each other
 Movement: resticted movement/vibrations, sliding
past each other, freely moving in random directions

8.  Note that:
 Particles in a:
› gas are well separated with no regular arrangement.
› liquid are close together with no regular arrangement.
› solid are tightly packed, usually in a regular pattern.
 Particles in a:
› gas vibrate and move freely at high speeds.
› liquid vibrate, move about, and slide past each other.
› solid vibrate (jiggle) but generally do not move from place
to place.

11.  A quick look
 https://www.youtube.com/watch?v=21CR01rl
mv4

12.  Diffusion is the movement of a substance from an area of
high concentration to an area of low concentration.
 Diffusion happens in liquids and gases because their
particles move randomly from place to place.
 What causes diffusion?
 In gases and liquids, particles move randomly from place
to place. The particles collide with each other or with their
container. This makes them change direction. Eventually,
the particles are spread through the whole container.
 Diffusion happens on its own, without stirring, shaking or
wafting.

15.  Brownian Movement in chemistry is said to
be the random zig-zag/randommotion of a
particle that is usually observed under high
power ultra-microscope. This movement
resembles the exact motion of pollen grains
in water as explained by Robert Brown,
hence, the name Brownian movement.

16.  State changes
 Substances can exist as a solid, liquid or gas.
Converting from one state to another usually
involves heating or cooling.
 Heat must be supplied to a substance for it to
melt, evaporate or boil. For example, you need
to heat ice to melt it, and you need to heat
water to make steam.
 Heat must be removed from a substance to
condense or freeze it. In other words, the
substance must be cooled down.

17.  The kinetic particle theory explains the
properties of the different states of matter. The
particles in solids, liquids and gases have
different amounts of energy. They are arranged
differently and move in different ways.
 The table below summarises the arrangement
and movement of the particles in solids, liquids
and gases, and shows simple diagrams for the
arrangement of the particles.

21.  https://www.bbc.co.uk/bitesize/guides/zthyj6f
/test