Science 7 · Unit 3: Forces and energy · Cambridge Lower Secondary Science Stage 7

Questions

1. 1. A diagram shows the direction of Mercury's orbit around the Sun with an arrow. Which way do the other planets orbit?

   • some the same way and some the opposite way
   • all in the same direction as Mercury
   • the inner planets the same way, the outer planets the opposite way
   • all in the opposite direction to Mercury
   Check

2. 2. 'Scientists think the Solar System formed from a cloud of dust and gas.' What kind of statement is this?

   • a hypothesis
   • a measurement
   • an investigation
   • an observation
   Check

3. 3. Which force pulls particles of dust and gas together in space?

   • gravity
   • friction
   • magnetism
   • air resistance
   Check

4. 4. 'Scientists use computers to show how the Solar System formed.' What is this?

   • modelling
   • observing
   • evidence
   • a hypothesis
   Check

5. 5. What is a nebula?

   • a cloud of dust and gas in space
   • a young planet
   • a group of moons
   • the path of a planet around the Sun
   Check

6. 6. Which equipment helps scientists see stars forming in distant clouds more clearly?

   • a force meter
   • a microscope
   • a telescope
   • a hand lens
   Check

7. 7. Astronomers look through a telescope and see young stars in a nebula. What is this?

   • a conclusion
   • an observation
   • a prediction
   • a fair test
   Check

8. 8. Scientists compare stars forming in different nebulas. Which of these can they not do?

   • carry out a fair test
   • make observations
   • make predictions
   • draw conclusions
   Check

9. 9. Why do scientists use computer models to study how the Solar System formed?

   • Models do not need any laws of physics.
   • It took millions of years and nobody could watch it happen.
   • It happened in a laboratory.
   • Computers are always right.
   Check

10. 10. Match each statement to what it is.

    • The Solar System formed from a cloud of dust and gas.
    • Computers show how the Solar System formed.
    • Stars can be seen forming in clouds in space.
    • All planets orbit the Sun in the same direction.

    • hypothesis
    • modelling
    • observing
    • evidence
    Check

11. 11. As particles of dust and gas stick together, what happens to their pull of gravity?

    • It gets stronger, because their mass increases.
    • It gets weaker, because they are bigger.
    • It disappears once they touch.
    • It stays the same.
    Check

12. 12. A ball of dust and gas keeps growing. What decides whether it becomes a star or a planet?

    • whether it has moons
    • how far it is from Earth
    • its size — beyond a certain size it gets hot enough to become a star
    • its colour
    Check

13. 13. All the planets orbit the Sun in the same plane. What does 'the same plane' mean?

    • They all have the same number of moons.
    • They all move on one flat surface, so the Solar System looks flat.
    • They all move at the same speed.
    • They are all the same size.
    Check

14. 14. Which fact seems to contradict the hypothesis that the Solar System formed from one spinning cloud?

    • All the planets orbit the Sun in the same direction.
    • All the planets orbit in the same plane.
    • Venus spins on its axis in the opposite direction to most planets.
    • Most moons orbit in the same direction as the planets.
    Check

15. 15. Which statement about the hypothesis of how the Solar System formed is correct?

    • No evidence supports it.
    • Most, but not all, of the evidence supports it.
    • It can be fully tested by experiments.
    • It has been proven to be correct.
    Check