The Particle Model
States of matter
Mixtures and solutions
Separating mixtures
Mystery science
100
True or false?
Solids don't move on their own so they do not have any kinetic energy
False
100
What are the three common states of matter?
Solid, Liquid and Gas
100
What is a mixture?
Two or more substances combined without chemically reacting with each other.
100
What separation technique would you use to separate stones from sand?
Sieving
100
True of false: A liquid has a fixed volume but not a fixed shape.
True
200
How are the particles arranged in a solid compared with a gas?
Solid particles are packed closely together; gas particles are spread far apart
200
What is the change of state from a solid to a liquid called?
Melting
200
What is a colloid?
A suspension that does not separate easily
200
What separation technique is commonly used to separate an insoluble solid from a liquid?
Filtration
200
What is the 4th state of matter?
Plasma
300
What are the main particle model features of a liquid?
Particles in liquids are close together but can move around each other
300
What is hardness?
The ability for a substance to scratch another substance
300
In a glass of salt water, what is the solvent and what is the solute?
Water is the solvent, salt is the solute
300
What two separation methods are used to recover salt from salt water?
Evaporation and Crystallisation
300
What is diffusion?
Diffusion is when particles in a mixture spread to become evenly distributed throughout the mixture
400
A student says, "When water evaporates, the water particles disappear." Is this correct? Explain your answer.
No they are incorrect. The particles do not disappear, they spread out and move through the air as a gas instead.
400
A cold glass of water is left outside on a warm day. Water droplets appear on the outside of the glass. Where did this water come from?
Water vapour in the air condensed on the cold surface of the glass.
400
A student mixes sand and water. Is this a solution? Explain why or why not.
No. Sand does not dissolve in water, so it forms a mixture rather than a solution.
400
A mixture contains sand, iron filings and small pieces of plastic. Which separation technique would you use and in what order?
Magnetism first to separate the iron filings and then a sieve to separate the sand and plastic
400
A student puts an ice cube on a plate. After some time, there is liquid water on the plate. Using the kinetic theory of matter, explain what happened?
The ice has melted because it has gained thermal energy, this causes the particles to move faster and eventually escape as a gas
500
Using the particle model, Explain why a gas can be compressed but a solid is very difficult to compress.
Gas particles have large spaces between them, which can be reduced. Solid particles are already packed very closely together.
500
A puddle of water disappears after sitting in the sun. Using the particle model, explain what has happened to the water particles.
The particles gained energy, moved faster and escaped from the liquid surface into the air as a gas.
500
Compare at least three similarities/differences between the solubility of particles in suspensions, colloids, emulsions and solutions
Suspensions, colloids, emulsions and solutions are similar because they all are mixtures. The differences involve the nature of the mixture.
A suspension and solution are solids in a liquid. The difference is that the solid dissolves in a solution whereas it does not in a suspension.
A colloid is similar to a solution because there are solids in a solution and they do not separate. The difference is that in a solution the particles are dissolved whereas in a colloid they are not.
A colloid is a type of suspension. The difference is that sediment will be deposited from a suspension whereas a colloid will not separate.
An emulsion is a type of colloid; both involve particles in a liquid that do not separate. They differ because a colloid is solids in a liquid whereas the emulsion is a mixture of two liquids.
500
You have a mixture containing sand, salt and water. Design a method to separate and collect all three substances.
Filter the mixture to collect the sand, then use distillation to evaporate the salt from the mixture. As the water cools it then condenses and is collected.
500
A Bank crime has occurred where a signature has been forged. 4 suspects have been detained and their blue pens have been tested against the original ink from the forged cheque (x). Which suspect is most likley the culprit and why?
Suspect d