Biology:
1. Aerobic: Requiring oxygen.
2. Anaerobic: Not requiring oxygen.
3. Autotroph: An organism that produces its own food.
4. Biodiversity: The variety of life on Earth.
5. Cell: The basic unit of life.
6. DNA: Deoxyribonucleic acid, the genetic material of organisms.
7. Ecosystem: A community of living organisms and their physical environment.
8. Evolution: The process of change in organisms over time.
9. Gene: A unit of heredity.
10. Heterotroph: An organism that consumes other organisms for food.
11. Metabolism: The sum of all chemical processes in an organism.
12. Photosynthesis: The process by which plants convert light energy into chemical energy.
13. Respiration: The process by which organisms release energy from food.
14. Species: A group of organisms that can interbreed and produce fertile offspring.
15. Symbiosis: A close relationship between two different species.
Chemistry:
16. Atom: The smallest unit of an element.
17. Bond: A force that holds atoms together.
18. Catalyst: A substance that speeds up a chemical reaction.
19. Compound: A substance made up of two or more elements.
20. Element: A pure substance that cannot be broken down into simpler substances.
21. Ion: An atom or molecule with a net electrical charge.
22. Molecule: Two or more atoms held together by chemical bonds.
23. pH: A measure of acidity or alkalinity.
24. Reaction: A process that involves the rearrangement of atoms and molecules.
25. Solubility: The ability of a substance to dissolve in another substance.
Physics:
26. Acceleration: The rate of change of velocity.
27. Energy: The ability to do work.
28. Force: A push or pull that can cause a change in motion.
29. Gravity: The force of attraction between objects with mass.
30. Inertia: The tendency of an object to resist changes in motion.
31. Mass: The amount of matter in an object.
32. Motion: The change in position of an object over time.
33. Velocity: The rate of change of position.
34. Wave: A disturbance that travels through a medium.
35. Wavelength: The distance between two successive crests or troughs of a wave.
Earth Science:
36. Erosion: The process by which rock, soil, and other materials are transported by wind, water, or ice.
37. Fault: A fracture in the Earth's crust.
38. Fossil: The preserved remains or traces of ancient life.
39. Plate tectonics: The theory that the Earth's outer layer is made up of plates that move and interact.
40. Weathering: The process by which rock is broken down into smaller pieces.
Astronomy:
41. Asteroid: A small rocky body that orbits the Sun.
42. Comet: A celestial object made of ice and dust that orbits the Sun.
43. Galaxy: A large collection of stars, gas, and dust.
44. Planet: A celestial body that orbits a star.
45. Star: A giant ball of hot gas that produces its own light and heat.
General:
46. Data: Information collected during a scientific experiment.
47. Hypothesis: A testable prediction.
48. Observation: The act of noticing and describing something.
49. Theory: A well-substantiated explanation of some aspect of the natural world.
50. Variable: A factor that can change in an experiment.
