Year 9 Exam Review

5. The thin, outer solid layer of the Earth.
8. The process plants use to convert carbon dioxide and water into glucose and oxygen using sunlight.
9. The thick, semi-solid layer beneath the crust that moves slowly due to convection currents.
10. A sudden release of energy caused by movement of tectonic plates.
13. The flow of electric charge through a circuit.
15. The central part of the Earth made mostly of iron and nickel.
16. A weakened or inactive form of a pathogen used to stimulate immunity.
18. Atoms of the same element with different numbers of neutrons.
20. The distance between two corresponding points on a wave, such as crest to crest.

1. The movement of heat through fluids, causing the mantle to circulate and move tectonic plates.
2. The process by which unstable nuclei release energy or particles to become stable.
3. A microorganism that causes disease.
4. The number of wave cycles that pass a point per second, measured in hertz (Hz).
6. A measure of how much a material opposes the flow of current.
7. The electrical potential difference that pushes current through a circuit.
11. When one tectonic plate slides beneath another and melts in the mantle.
12. The smallest unit of an element that retains its chemical properties.
14. The light-sensitive layer at the back of the eye that detects images.
17. Part of the 3rd line of Defense, I am a protein made by the B Cells that helps destroy pathogens.
19. States that Voltage = Current × Resistance.