Which size reduction law states that the work required to reduce the size of a given quantity of material is constant for the same reduction ratio regardless of initial size?

• A. Kick's Law
• B. Rittiger's Law
• C. Bond's Law
• D. NOTA

Answer: (A)

The idea being tested is how energy for breaking down material scales with how much you reduce its size. Kick’s law says the work needed is proportional to the size-reduction ratio, so for the same ratio of starting size to final size, the work is about the same, regardless of how large the starting particle is. In other words, if you go from a big size to a smaller size with a 2:1 reduction (F to P), the energy required should be similar whether you started with large particles or smaller ones. This is often expressed as the work being proportional to the logarithm of the reduction ratio (W ∝ ln(F/P)).

This differs from the other laws: Rittinger’s law ties energy to the new surface area created, which depends on how fine you go and the starting size, so the initial size matters more there. Bond’s law uses a different relationship involving the inverse square root of sizes, not giving a constant energy for a fixed reduction ratio across different starting sizes.