61. The physical data term on a Safety Data Sheet (SDS) describing whether a liquid is lighter or heavier than water is __________.

Specific gravity indicates a liquid's density relative to water, determining if it is lighter or heavier. This measurement, found on Safety Data Sheets, compares a substance's density to water's density; a value less than 1.0 signifies a lighter substance, while a value greater than 1.0 indicates a heavier substance. Viscosity measures flow resistance, solubility describes dissolution, and flotation point is not a standard SDS term.