Question

what is density give its SI unit​

Answer 1

mass per unit volume of a substance is called density.

S. I unit of density :- kg/m^3

Answer 2

the degree of compactness of a substance...

mass per unit volume...

Density is a measure of mass per unit of volume. The average density of an object equals its total mass divided by its total volume. An object made from a comparatively dense material (such as iron) will have less volume than an object of equal mass made from some less dense substance (such as water).

The SI unit of kilogram per cubic metre (kg/m3) and the cgs unit of gram per cubic centimetre (g/cm3) are probably the most commonly used units for density.1,000 kg/m3 equals 1 g/cm3. (The cubic centimeter can be alternately called a millilitre or a cc.)

kg/m³