Year 7 Science · AC9S7I01

Investigable Questions, Predictions and Hypotheses

Refine questions, identify variables, use models and prior knowledge, and write reasoned predictions and hypotheses.

Part A — Accessible

  1. Which is more investigable: “Do plants like music?” or “How does 2 hours per day of recorded music affect average seedling height over 21 days?” Explain why.
  2. In “How does ramp height affect trolley travel time over 1 metre?”, identify the independent and dependent variables.
  3. State one difference between a reasoned prediction and a hypothesis.
  4. Why should a prediction be recorded before results are collected?

Part B — Standard

  1. Rewrite “Is warm water better?” as a measurable, feasible question about dissolving sugar.
  2. The particle model suggests heating a flexible balloon containing gas may change its volume. Write an investigable question based on this model.
  3. Write a reasoned prediction for how parachute surface area may affect descent time, including a scientific reason.
  4. A local authorised seasonal resource notes that a bird often arrives soon after a flowering event. Write a suitable pattern question that could be investigated using dated records.

Part C — Challenging

  1. A student changes both water temperature and sugar mass when testing dissolving time. Explain why this makes the relationship difficult to interpret.
  2. Write a hypothesis for the relationship between ramp height and trolley travel time. Use the format “If…, then…, because…”.
  3. Explain one limitation of using a scientific model to generate a hypothesis.
  4. Design outline: choose one everyday curiosity, turn it into an investigable question, identify variables or a measurable pattern, and write a reasoned prediction or hypothesis.

Answer key / marking guidance

1

The second question is more investigable because it specifies a comparison, exposure time, measurable outcome and time period.

2

IV: ramp height. DV: trolley travel time over 1 metre.

3

A prediction states the expected observation; a hypothesis proposes a testable relationship or explanation. They can be linked, but they are not identical.

4

Recording it before results preserves the original expectation so it can be honestly compared with evidence.

5

Example: “How does water temperature affect the time taken for a fixed mass of sugar to dissolve?”

6

Example: “How does the temperature of a fixed amount of trapped gas affect balloon volume in a flexible container?”

7

Example: “A larger parachute will take longer to descend because its greater surface area produces greater air resistance.”

8

Example: “How many days separate the recorded flowering event and bird arrival across several seasons at this location?” Keep the source and local context explicit.

9

Two variables are changing, so any change in dissolving time could be caused by temperature, sugar mass or both. The effect of one relationship cannot be isolated clearly.

10

Example: “If ramp height increases, then trolley travel time over 1 metre will decrease because the trolley starts with greater gravitational potential energy and can gain more speed.”

11

Models simplify reality and may omit variables or interactions; predictions generated from them still need evidence from the real system.

12

Answers vary. Full marks require a measurable/feasible question, correct variables or pattern, and a reasoned prediction/hypothesis linked to relevant scientific knowledge.