Because the density of this piece of plastic is under 1 g/cm3.
Water
When it floats in water.
liquid water is more dense than solid water
A solid that has a density greater than the density of the medium it is placed in (i.e. water). So a piece of lead is more dense than water, and so it sinks. Styrofoam is not very dense, and it floats.
All plastic items float on water, so therefore a plastic boat floats on water.
its a solid
no ice floats on water
Ice.
the density of water is higher than the density of wood... & so an iron piece sinks & a ton of wood floats...
A plastic spoon floats because it is less dense than the water it is on.
The piece of wood floats in water because its specific gravity is less than water.
Water floats when it is in the solid phase, called ice. Ice floats because the density of ice is less than the density of water.