Significant Figures: Significant figures are digits in a number that carry meaning and contribute to its precision. When dealing with negligible masses, they are often ignored since their impact on calculations would be insignificant.
Approximation: Approximation involves estimating values or quantities based on limited information or simplifying assumptions. Negligible masses are sometimes approximated as zero for simplicity.
Precision vs Accuracy: Precision refers to how close multiple measurements are to each other, while accuracy refers to how close measurements are to the true value. Negligible masses may affect precision but not necessarily accuracy.