What will happen if the density of an object is less than the density of water?

The object  will float on the surface of water if its density is less than the equal volume of water.

Explanation:

Density:

It is define as mass per unit volume.

d=m/v

it is mostly measure in g/mL

it is represented by ρ (rho)

The density of water is one gram per cubic centimeter. If the object is less denser than water it will float. If the density of object is greater than the density of water it will sink.

Other examples:

some rocks are more denser then water so they will sink in it.

density of oil is less than vinegar, so it will float on the surface of vinegar