7STEM – Revising Chemistry

Which of the following diagrams correctly represents particles in three states: solid, liquid, and gas?

• Diagram A: Particles are closely packed in solid, slightly apart in liquid, and far apart in gas.

• Diagram B: Particles are far apart in solid, closely packed in liquid, and slightly apart in gas.

• Diagram C: Particles are slightly apart in solid, far apart in liquid, and closely packed in gas.

Look at the heating curve of water below: What is happening at the sections where the graph is flat?

• The temperature is increasing.

• The temperature is decreasing.

• The temperature remains constant.

• The water is boiling.

Name the parts of the Bunsen burner labelled in the diagram below. Parts: A, B, C, D, E.

• A: Base, B: Gas inlet, C: Air control, D: Barrel, E: Collar.

• A: Base, B: Air control, C: Gas inlet, D: Collar, E: Barrel.

• A: Collar, B: Base, C: Barrel, D: Gas inlet, E: Air control.

• A: Gas inlet, B: Collar, C: Base, D: Air control, E: Barrel.

The yellow flame from a Bunsen burner can be considered to be the safety flame because:

• it is not hot enough to burn.

• it is easily visible and indicates the burner is on.

• it produces less light than a blue flame.

• it is used for heating purposes.

What was the independent variable in this investigation?

• Temperature

• Time

• Concentration

• Pressure

What was the dependent variable in this investigation?

• The variable that was changed

• The variable that was measured

• The variable that was controlled

• The variable that was ignored

Suggest 2 things Dennis and Zoe would need to keep the same to ensure that this was a fair test.

• The type of equipment used and the time of day the test is conducted

• The weather conditions and the type of equipment used

• The time of day the test is conducted and the weather conditions

• The type of equipment used and the location of the test

What conclusion can you make from these results?

• The results indicate a positive trend.

• The results show no significant change.

• The results suggest a negative outcome.

• The results are inconclusive.

A puddle dries up on a hot day because of:

• evaporation

• condensation

• freezing

• sublimation