Define density of a substance.

density, mass of a unit volume of a material substance. The formula for density is d = M/V, where d is density, M is mass, and V is volume. Density is commonly expressed in units of grams per cubic centimetre. ... Density can also be expressed as kilograms per cubic metre (in metre-kilogram-second or SI units).

Explanation:

density is how compact a substance is

Explanation: the formula used to find density is d=m/v where d is density, m is mass and v is volume

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year