Final answer:
Discrepancies between the recovered and original sample mass can be caused by measurement uncertainties, variations in isotope natural abundance, and irregularities or external factors affecting the experiment.
Step-by-step explanation:
When considering the difference between the total mass of a sample recovered compared to the original mass, several factors could account for potential discrepancies due to experimental error. Firstly, the measurement uncertainty intrinsic to the equipment used, such as balances, can lead to small variations. For example, if a balance is accurate to 1 g, the actual mass may be within a range around the displayed mass, introducing a potential error in the reported measurement.
Another possible source of error is the variability in natural abundance of isotopes. Differences in isotopic composition can lead to variations in mass measurements, especially when high precision is required. Although mass is conserved in reactions, slight variations in isotopic ratios from different sample sources could alter the expected mass.
Lastly, there may be irregularities in the object being measured or other factors specific to the experimental setup that could affect the outcome. This could include variations in the purity of the sample, environmental conditions such as temperature or humidity, or even procedural inconsistencies during the experiment.