States of Matter
Define a solid, liquid, and gas.
A solid has a fixed shape and volume, a liquid has a fixed volume but takes the shape of its container, and a gas has no fixed shape or volume.
Name the change of state from solid to liquid.
Melting
Define a solution and give one example
A solution is a mixture where a substance is dissolved in another. Example: saltwater.
Name one method used to separate sand from water.
Filtration.
Name a piece of equipment used to measure liquid volume. (1 mark)
Measuring cylinder.
Describe how particles are arranged in a liquid
In a liquid, particles are close together but not in a fixed position. They can move past each other.
Describe what happens to particles during evaporation
During evaporation, particles gain energy and move faster, allowing some to escape from the surface of the liquid into the air.
Identify the solute and solvent in saltwater.
In saltwater, salt is the solute and water is the solvent.
Describe how filtration works.
Filtration works by passing a mixture through filter paper, which traps solid particles while the liquid passes through.
Describe the function of a Bunsen burner. (2 marks)
A Bunsen burner is used to heat substances in the laboratory.
Compare the movement of particles in solids and gases
In solids, particles vibrate in fixed positions. In gases, particles move freely and quickly in all directions.
Explain the difference between boiling and evaporation
During evaporation, particles gain energy and move faster, allowing some to escape from the surface of the liquid into the air.
Explain the difference between a pure substance and a mixture.
A pure substance contains only one type of particle, while a mixture contains two or more substances physically combined.
Explain how evaporation can be used to obtain salt from saltwater.
When saltwater is heated, the water evaporates and leaves the salt behind as a solid.
Explain how to safely heat a substance in a test tube. (3 marks)
Hold the test tube at an angle, point it away from people, and move it through the flame to heat it evenly.
Explain why gases can be compressed but solids cannot.
Gases can be compressed because there is a lot of space between particles. Solids cannot be compressed because their particles are tightly packed together.
Describe the energy changes that occur during melting and freezing.
During melting, particles gain energy and move more freely. During freezing, particles lose energy and slow down, becoming fixed in place.
Describe how concentration affects the properties of a solution.
Higher concentration means more solute particles are present, which can make the solution stronger (e.g. taste, colour, or conductivity).
Compare filtration and distillation in terms of what they separate.
Filtration separates an insoluble solid from a liquid, while distillation separates liquids based on different boiling points.
Compare the uses of a measuring cylinder and a beaker. (3 marks)]
A measuring cylinder is used for accurate volume measurements, while a beaker is used for holding and mixing substances.
Using particle theory, explain why liquids take the shape of their container but keep a fixed volume.
In liquids, particles are close together so the volume stays the same. However, they can move past each other, allowing the liquid to take the shape of its container
Using particle theory, explain why temperature remains constant during boiling.
During boiling, energy is used to break the forces between particles rather than increase temperature, so the temperature stays constant.
Explain, using particle theory, how a solute dissolves in a solvent.
A solute dissolves when its particles spread out and mix evenly between the solvent particles.
Explain why distillation can separate two liquids with different boiling points.
In distillation, the liquid with the lower boiling point evaporates first, then cools and condenses back into a liquid, separating it from the other liquid.
Explain why accuracy and precision are important when using laboratory equipment. (4 marks)
Accuracy ensures results are close to the true value, and precision ensures results are consistent. Both are important for reliable experiments.