Summary Pearson edexcel Chemistry IGCSE revision notes

,
,·
States of matter




·

Interconversions

g
=> =
by heating
=
by cooling
auton




Melting -
Particles vibrate so fast that the force of attraction
between the particles are no
longer strong enough to
hold them together
·


Particles are able to move around each other


freezing- Particles more so slowly that the forces of attraction
between them will hold them in a fixed position
Particles pack closer together
-




Bailing -

Particles more fast enough to overcome all the forces
of attraction between them

, Condensation particles -

slowly enough that forces of
more


attraction between them start to form
-



they are held in a liquid


Evaporation - fast particles at the surface of liquid will have a



enough energy to overcome the forces of attraction between
the particles
-




Particles break away to form gas a




Sublimation - solid changes directly to a
gas
at normal pressure

without liquid
involving any is the process



Desublimation -



reverse of sublimation

-



Diffusion of gases




Ammonia particles are lighter => more faster >
=




diffused further in the

same amount of time
·


Dilution of cloured
Solutions Diffusion is slow in liquids because
·

particles more slower
·

closer together so more collisions