Calculate the number of molecules present in 1.55 x 10-3 g HCI.

Ithink it is quantity of plants

Okay well gravitational energy is matter forced by gravity making energy though the kinetic energy then the electric energy produces electricity from the kinetic energy and the kinetic energy gets its energy from the gravitational energy. was that the answer you wanted or something else?  

Answer ozone (o3) is made of three atoms of oxygen, it is a molecule;

The law of conservation of mass states that a mass of an object or the amount of matter composed inside an object or thing will not change unless it is added or removed of the matter that is contained in the object itself.