1. Which type of particle is emitted in the nuclear decay reaction shown here?
'>

2. A comet is a small celestial body made of ice and dust that orbits the sun in an elliptical or oval path. Because the path is not perfectly circular, sometimes the comet is closer to the sun, and sometimes it is farther away from the sun. As the comet approaches the sun, the comet begins to warm up, and some of the dust and ice begins to stream away, forming the long, distinctive comet tail. Some scientists consider comets to be the most interesting of the celestial bodies.
Based on this information, which of the following statements is an opinion rather than a fact?

3. Which of the following did not play a significant part in Charles Darwin’s theories of evolution?

4. On a particular island, lions prey on zebras. If a deadly virus that affects only zebras were to spread through the island, what effect would that have on the lion population?

5. What is the main genetic advantage that sexual reproduction has over asexual reproduction?

6. According to the best scientific estimates, approximately how old is the universe?

7. Why is copper used for electrical wiring in electric circuits?

8. Evolutionary fitness is determined by how much an individual contributes to the gene pool of the next generation. The more living offspring an individual produces, the fitter that individual is. According to this definition, which of the following individuals is currently the fittest?

9. Which of the following is an example of an organism?

10. Sammy was boiling some brine (seawater) but forgot that he left the heat on. When he returned to the pan 40 minutes later, he noticed a white residue left at the bottom of the pan.
Which of the following best explains the white residue?

11. Which of the following correctly represents the hierarchy in living organisms, classified from smallest to the largest?

12. Which of the following statements is correct?

13. The mass number of an element is the sum of the number of within the nucleus of the atom.

14. Jim likes to make fruit jelly. He uses a pressure cooker as part of the process. If he follows the correct procedure, the jelly will be properly sterilized and will be good to eat at a later date.
Why does Jim use the pressure cooker?

15. If the distance between the two objects is doubled, what effect will this have on the gravitational force between them?

16. The acceleration due to gravity on the moon is much smaller than it is on Earth. There is also no air resistance on the moon (because there is no air on the moon).
If an astronaut hits a golf ball on the moon, how will the ball’s path differ compared to its path if the ball had been hit here on Earth?

17. Which type of particle is emitted in the nuclear decay reaction shown here?
>

18. What causes a solar eclipse?

19. Which of the following systems includes the plants and animals of Earth?

20. Which of the following explains why, every fourth year, we have a leap year that has 366 days rather than the usual 365 days?

21. When Alex works out at the gym, he sometimes lifts weights. As he lifts the barbell to its highest point, several energy transitions take place. Which of the following lists these energy transitions in the correct order?

22. Earthworms help to break down the bodies of dead organisms such as leaves, returning nutrients to the soil in the process.
Based on this information, what role do earthworms play in the food chain?

23. If the south poles of two strong magnets are placed close together on a smooth table, what will happen?

24. Which of the following is a simple machine?

25. Which of the following is an example of a positive feedback mechanism in the climate system of Earth?