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Topic 2a - States of matter and mixtures - Coggle Diagram
Topic 2a - States of matter and mixtures
the three states of matter
Solids
strong forces of attraction between particles
definite shape and volume
particles vibrate, as temperature increases, they vibrate more
Expand slightly when heated
Liquids
weak forces of attraction
randomly arranged particles, free to move
definite volume, but not a definite shape
constantly moving with random motion
Gases
very weak forces of attraction
particles are to move
no definite volume and no definite shape
particles have more energy that in a solid or liquid state
Changes of state
solid to liquid, melting
When a solid is heated, particles gain energy and vibrate more
Forces of attraction are weakened
Solid expands
Particles have enough energy to break free from their positions
liquid to gas, boiling
Particle move faster when they gain more energy
Attractive forces are weakend
At a certain temperature known as boiling point, the particles have enough energy to overcome the forces between them
gas to liquid, condensing
As a gas cools, its particles no longer have enough energy to overcome the forces of attraction between them
At a certain temperature, the forces between the gas particles are strong enough that the gas becomes a liquid
liquid to solid, freezing
When a liquid cools, there isn't enough energy to overcome the attraction between the particles, so the particles are less free to move
At the freezing point, the forces between the particles becomes strong enough that the particles are held in place
Physics changes - involve the forces between the particles of the substances but the particles themselves don't change
Chemical changes - where a new product has been formed
Purity
a substance is pure if it completely made up of a single element or compound
if a substance contains more than one compound, then it is described as a mixture
testing for purity
a chemically pure substance will have a specific, sharp boiling or melting point
if a substance is a mixture, it will melt gradually over a range of temperatures
process
measure the melting point sample
heat up the sample very slowly so its easy to see the exact temperature the sample stars to melt at
if the melting point is the same as expected, it's pure
water treatment
sources of water
surface water
lakes, rivers and reservoirs
these sources start running dry in summer months
ground water
from rocks that trap water underground
very limited supply
waste water
treating waste water is often better for the environment than simply disposing it
the levels of contamination affects how the water is treated
water purification
2) filtration - small insoluble particles are removed by filtering through beds of sand
1) sedimentation, large insoluble particles sink to the bottom of a tank
3) chlorination, chlorine gas is bubbled from the water to kill microbes
distilling sea water
sea water can distilled to provide potable water
sea water is boiled, the water evapourates and is seperated from the salt
requires alot of energy and is very expensive
Potable water
Water suitable for drinking
Low levels of microbes and contamingating substances
Not the same as pure water, but still safe
Diffusion
The random movement of particles from an area of high concentration to an area of low concentration