NS Term 2 Flashcards
(28 cards)
Describe the particles in a solid object:
- Packed tightly together
- Very small space between particles
- Particles vibrate in one place
- Particles have little energy of motion
Describe the particles of a liquid object:
- Particles have no fixed pattern
- Spaces between particles are small
- Particles move around and glide over each other
- Particles have more energy of motion than in solids
Describe the particles of a gas object:
- There is no order for particles to move in
- The spaces between the particles are large
- Particles move very fast and freely in all directions
- Particles have lots of energy of motion
What two changes of state are needed for a solid to change into a gas?
solid (melting) > liquid (evaporation) > gas
What two changes of state need to happen for a gas to become a solid?
gas (condensation) > liquid (freezing/crystallising) > solid
What happens when particles are heated?
They gain energy of motion and change state (Eg: melting)
What is another name for energy of motion?
Kinetic energy
What happens when particles are cooled?
They lose kinetic energy and change state (Eg: condensation)
What is a mixture?
Two or more substances with different properties that are mixed together
Do the substances in mixtures react chemically?
No they don’t
What are some ways mixtures can be seperated? (Study page 214 further)
- Hand sorting
- Sifting
- Seperating funnel
- Filtration
- Magnetism
- Evaporation
What is a “solution”? (In terms of mixtures)
When two substances are mixed and form a new substance
(Eg: Water + Coffee grounds = Coffee)
In this case; coffee grounds = soluble substance / water = solvent
What are substances that cannot dissolve in water called?
Insoluble solids
What is a solution of metals called?
An alloy
What is a “Saturated Solution?”
When no more of the solute can dissolve in the solvent at a specific temperature
What is the point called where no more solute can be dissolved?
The saturation point
What is “Crystallisation?”
When crystals form from a solution
What are the three factors that affect the rate of dissolving?
- Temperature
- Stirring or shaking the mixture
- Grain size of the solute
What is water pollution?
When water resources are contaminated and dirty
How are some ways water can be polluted?
Soluble substances (like chemicals)
Insoluble substances (like litter and waste)
Living germs (like bacteria)
What are some causes of water pollution? (Study page 262 for more info)
Sewage
Industries and mines
Oil
Litter
Agriculture
What effects do water pollution have?
A negative affect on sealife and coastlines
Poisoning wildlife
Causes waterborne disease
Leads to death of wildlife and humans
What is a natural solution to water pollution?
Wetlands
What are wetlands important for?
The removal of waste from water
The regulation of flow of water
