Question

Cork is a colloid of:

• A. Solid in solid
• B. Liquid in solid
• C. Solid in liquid
• D. Gas in solid

Hint:

Cork is an example of a solid matrix with gas trapped inside, forming a colloidal solution.

Answer 1

The Correct Option is D

Cork is a colloid of: 

• Option 1: Solid in solid - This refers to a solid dispersion within another solid, like alloys. This is not the correct answer for cork.
• Option 2: Liquid in solid - This refers to a liquid dispersed in a solid, like gels or some food products. This is not the correct description for cork.
• Option 3: Solid in liquid - This describes a suspension, which is not what cork is made of.
• Option 4: Gas in solid - This is the correct answer. Cork is a solid that contains gas trapped within its cellular structure, making it a colloidal system with gas dispersed in a solid form. This is why cork is light and buoyant.

Explanation:

Cork is a colloidal solution in which gas is trapped in a solid matrix. This makes it a gas in solid colloid. The gas trapped in the cork's cellular structure gives it its lightweight and buoyant properties.

Answer 2

Cork is being classified by its physical state combination. Check each option against cork's actual cellular structure.

1. Solid in solid: this would need one solid embedded in another, like an alloy, but cork's lightness comes from something other than a second solid component.
2. Liquid in solid: this would need liquid trapped in a solid network, like cheese, but cork does not feel moist or soft the way a liquid-holding gel does.
3. Solid in liquid: this would describe a suspension-like mixture, unrelated to cork's dry, rigid, lightweight structure.
4. Gas in solid: cork's cellular walls trap tiny pockets of air throughout a solid structure, which is exactly why cork feels so light and floats easily. This matches cork directly.

Cork's lightness and buoyancy come from air trapped within its solid cell walls.

So the correct answer is gas in solid.