1. Which of the following questions is NOT appropriate for scientific investigation?

A. How can we reduce greenhouse gas emissions?
B. Is there intelligent life beyond Earth?
C. What is the meaning of life?
D. Does free will exist?

Correct answer: C

Rationale: Science deals with observable, measurable phenomena using evidence-based methods. Questions about subjective experiences and abstract concepts like meaning fall outside the realm of scientific inquiry.

2. The element responsible for the yellow color of bananas is:

A. Potassium
B. Calcium
C. Phosphorus
D. Carotene

Correct answer: D

Rationale: Carotene is a type of carotenoid pigment found in fruits and vegetables, contributing to their yellow, orange, and red hues.

3. Which element is used in fluorescent lamps and emits ultraviolet light when excited?

A. Mercury
B. Neon
C. Argon
D. Krypton

Correct answer: A

Rationale: Mercury vapor in fluorescent lamps generates UV light that excites phosphors on the lamp's inner surface, producing visible light.

4. What property of a substance refers to its ability to be drawn into thin wires without breaking?

A. Malleability
B. Viscosity
C. Ductility
D. Conductivity

Correct answer: c

Rationale: Ductility is the property that describes a substance's ability to be drawn into thin wires without breaking.

5. Which property of a wave determines its loudness in sound waves?

A. Amplitude
B. Wavelength
C. Frequency
D. Speed

Correct answer: a

Rationale: Amplitude in sound waves relates to the loudness or intensity of the sound.

6. A salt solution that conducts electricity well is most likely

A. A saturated solution
B. A concentrated solution of a strong electrolyte
C. A dilute solution of a weak acid
D. A mixture of a neutral compound and water

Correct answer: B

Rationale: The correct answer is B: "A concentrated solution of a strong electrolyte." Strong electrolytes completely dissociate into ions in solution, thereby increasing the conductivity of the solution. Concentrated solutions have a higher amount of dissolved solute particles, which leads to more ions available for conducting electricity. In contrast, saturated solutions may contain undissolved solute, limiting the number of ions in solution. Dilute solutions have fewer ions and weak acids only partially dissociate, reducing conductivity. A neutral compound and water do not provide ions for conducting electricity. Therefore, a concentrated solution of a strong electrolyte is most likely to conduct electricity well due to the high concentration of ions present.