Complete
Chemistry
Notes
States of matter
Everything is made of particles.
Particles in solid are not free to move around. Liquids and gases can. As
particles move they collide with each other and bounce off in all directions.
This is called random motion
.
In 2 substances, when mixed,
particles bounce off in all directions when they collide. This mixing process
is called diffusion .It’s also the movement of particles without a force. The
smallest particle that cannot be broken down by chemical means is called an
atom. ·In some substances, particles are just single atoms. For example the gas
argon, found in air, is made up of single argon atoms.
·In many substances, particles
consist of 2 atoms joined together. These are called molecules .·In other
substances,particles consist of atoms or groups of atoms that carry a charge. These
particles are called ions.
Solids liquids and gases
Solid
Properties:
•Definite shape and volume
•Normally hard and rigid
•Large force required to change
shape
•High Density
•Incompressible
Model:
•Closely packed
•Occupy minimum space
•Regular pattern
•Vibrate in fixed position
•Not free to move
Liquid
Properties
:
•Definite volume but no shape.
•High Density
•Not compressible Model:
•Occur in clusters with molecules
slightly further apart compared to
solids
•Free to move about within a
confined vessel
Properties:
•No Fixed volume and no fixed shape
•Low density
•Compressible
Model:
•Very far apart
•Travel at high speed
•Independent and random motions
•Negligible forces of attraction
between them
Diffusion in
Gases
Gases diffuse in different rates.
Those rates depend on
Their factors:
1. The lower the mass of its
particles the faster a gas will diffuse.
Mass of the particles
Why?
Because the lighter the
molecules...the faster it will travel
(obviously
...)
2.
The higher the temperature, the
faster a gas will diffuse.
The temperature
Why?
Because particles gain energy as
they are heated
Mixtures,
Solutions, and Solvents
Mixture
:
Contains more the one substance.
They are just mixed together
and not chemically combined.
Example
: Sand and water.
Solution
: It is when a solute and a solvent
mix. The solute dissolves in the solvent
making a solution.
Example
:sugar (solute) dissolves in water
(solvent) making a solution of sugar
and water.The solubility of every
substance is different. To help a solute dissolve you could
:•Stir it
•Rise the temperature
If you add excess amount of sugar in
a small amount of water...it
won’t dissolve as there is no space
for it. The solution becomes
saturated
.
Solvent
: A substance that allows solutes to
dissolve in
Example: Water, Ethanol
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