Density is its mass per unit volume.
ρ = m⁄v
where ρ = density of object (in kgm-3)
SI Unit: kg m-3
For pure substance, it is a fixed property.
Different outcomes when an object placed in a liquid:
density of object ˂ density of liquid => float
density of object = density of liquid => suspend
density of object ˃ density of liquid => sink
Note that when an object is made of more than one material, then consider its average density.
Average density = total mass⁄total volume