Question

a student lists a set of materials.

1. wood
2. hydrogen gas
3. milk
4. water

which material(s) can be a medium through which a wave can travel?
○ hydrogen gas
○ milk and water
○ wood, hydrogen gas, milk, and water
○ wood

Explanation:

Step1: Recall wave medium concepts

Mechanical waves require a medium (solid, liquid, gas). Wood (solid), milk (liquid), water (liquid) can be media. Hydrogen gas (gas) can also be a medium. But the question is about which set includes all possible media.

Step2: Analyze each option

• Option "wood": Only solid, misses liquid and gas.
• Option "milk and water": Only liquids, misses solid and gas.
• Option "hydrogen gas": Only gas, misses solid and liquid.
• Option "wood, hydrogen gas, milk, and water": Includes solid (wood), gas (hydrogen), liquids (milk, water) which are all possible media for mechanical waves.

Answer:

wood, hydrogen gas, milk, and water