1. Which vitamin is essential for calcium absorption and bone health?

A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin E

Correct answer: C

Rationale: The correct answer is Vitamin D. Vitamin D plays a crucial role in calcium absorption in the intestines, which is essential for maintaining strong and healthy bones. It helps regulate calcium and phosphorus levels in the body, promoting bone mineralization and growth. Vitamin A is important for vision and immune function, not specifically for bone health. Vitamin C is essential for collagen synthesis but not directly involved in calcium absorption. Vitamin E is an antioxidant that protects cells from damage but does not have a direct role in bone health. Therefore, Vitamin D is the correct choice for supporting calcium absorption and bone health.

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. Which term describes the point where parallel rays of light converge or appear to diverge from after passing through a lens or reflecting off a mirror?

A. Aperture
B. Focal length
C. Refractive index
D. Lens thickness

Correct answer: B

Rationale: The focal length is the term that describes the point where parallel rays of light converge or appear to diverge from after passing through a lens or reflecting off a mirror. It is a crucial parameter in optics and is used to determine the magnification and image formation in optical systems. The other options (A) Aperture, (C) Refractive index, and (D) Lens thickness are not directly related to the point where parallel rays converge or diverge.

4. The process by which a solid changes directly into a liquid is called:

A. Melting
B. Condensation
C. Sublimation
D. Deposition

Correct answer: D

Rationale: While melting is a solid to liquid transition, deposition, also known as sublimation, refers to a gas directly changing into a solid.

5. Where should a semicolon be placed in the following sentence? "He loves reading comics, playing video games, and spending time with friends"?

A. He loves reading comics; playing video games, and spending time with friends.
B. He loves reading comics, playing video games; and spending time with friends.
C. He loves reading comics, playing video games and spending time with friends.
D. No semicolon needed.

Correct answer: B

Rationale: Semicolons can join three or more items in a list, especially when the items themselves contain commas. Option (b) is the correct placement.

6. What does the term "dilution" refer to in a solution?

A. Adding more solvent to decrease concentration
B. Adding more solute to increase concentration
C. Reducing the temperature to increase solubility
D. Increasing pressure to increase solubility

Correct answer: A

Rationale: Dilution involves adding more solvent to a solution to decrease the concentration of solute. The other choices do not accurately describe dilution