1. What is a potential limitation of using case studies in scientific research?

A. They offer unique insights and perspectives not found in large-scale studies.
B. They can be easily replicated and validated by other researchers.
C. They often present limited data points and may not be generalizable to larger populations.
D. They require sophisticated statistical analysis, making them difficult to interpret.

Correct answer: C

Rationale: While case studies provide valuable individual details, their small sample size and specific context limit their ability to represent broader trends or populations.

2. Which element makes up the majority of the Earth's atmosphere?

A. Nitrogen
B. Oxygen
C. Carbon dioxide
D. Argon

Correct answer: A

Rationale: Nitrogen is the most abundant gas in the Earth's atmosphere, crucial for plant life and maintaining the planet's temperature balance.

3. What is the SI unit of measurement for momentum?

A. Newton (N)
B. Kilogram-meter per second (kgÃ‚Â·m/s)
C. Joule (J)
D. Newton-second (NÃ‚Â·s)

Correct answer: b

Rationale: Momentum is measured in kilogram-meter per second (kgÃ‚Â·m/s).

4. What is the term for a group of organisms living in the same place and interacting with each other?

A. Ecosystem
B. Community
C. Population
D. Niche

Correct answer: B

Rationale: Rationale: - A) Ecosystem refers to a biological community of interacting organisms and their physical environment. - B) Community specifically refers to a group of organisms of different species living in the same place and interacting with each other. - C) Population refers to a group of individuals of the same species living in the same area. - D) Niche refers to the role or function of an organism or species within an ecosystem. In this context, the term for a group of organisms living in the same place and interacting with each other is best described as a community because it involves multiple species interacting within a shared habitat.

5. A scientific theory is:

A. A personal belief or hunch about how something works.
B. A well-substantiated explanation based on evidence and repeated testing.
C. A single experiment's findings not yet confirmed by others.
D. A fixed and unchanging dogma beyond questioning.

Correct answer: B

Rationale: Theories in science are constantly evolving and open to revision as new data emerges, unlike personal beliefs or fixed dogmas.

6. A lab needs 200ml of a 5% salt solution. They only have a 10% solution. How much 10% solution and water should be mixed?

A. 100ml 10% solution, 100ml water
B. 150ml 10% solution, 50ml water
C. 160ml 10% solution, 40ml water
D. 200ml 10% solution, 0ml water

Correct answer: B

Rationale: Rationale: 1. Let x be the volume of the 10% solution needed and y be the volume of water needed. 2. The total volume of the final solution is 200ml, so x + y = 200. 3. The concentration of the final solution is 5%, so the amount of salt in the final solution is 0.05 * 200 = 10g. 4. The amount of salt in the 10% solution is 0.1x, and the amount of salt in the water is 0, so the total amount of salt in the final solution is 0.1x. 5. Since the total amount of salt in the final solution is 10g, we have 0.1x = 10. 6. Solving for x, we get x = 100ml. 7. Substituting x =