Question

Fill in the blank.

If a substance's density is less than one then the substance is _________ than reference.

• A. less dense
• B. more dense
• C. more heavy
• D. less heavy

Answer 1

The correct option is A less dense

Relative density(${\rho }_r$) of a substance is defined as ratio of density of the substance($\rho$) to the density of reference material$\left({\rho }_{ref}\right)$.

${\rho }_r=\frac{\rho }{{\rho }_{ref}}<1$

$⟹\rho <{\rho }_{ref}$
Hence the substance is less dense than the reference.