Why compare percentage change in mass rather than absolute mass of each chip?

Comparing percentage change in mass rather than the absolute mass of each chip is important primarily to accommodate variations in chip sizes. Chips used in experiments can vary significantly in size and mass due to inherent differences in the materials, manufacturing processes, or experimental handling. By focusing on the percentage change, these variations are normalized, allowing for a more accurate comparison of the effects being studied across different chips.

For example, if one chip starts at a mass of 10 grams and another at 5 grams, an absolute mass change might suggest that the first chip is undergoing a more significant effect, but the percentage change provides a context that takes the initial differences into account. This means that even small chips that might experience a large relative change can be directly compared to larger chips, thus ensuring that the conclusions drawn from the data reflect proportional changes rather than absolute figures that could skew interpretations due to size discrepancies.