Mass is the combined measure of number of atoms and density of those atoms contained by an object.
Commonly it is stated that “Mass is the measure of amount of matter”.
In depth, the “matter” stands for combination of number of atoms and density of those atoms.
Mass is always constant, Hence if the gravity changes, there wouldn’t be any effect on mass, it will be the same at all places.
If mass of an object is more then amount of force acting on the object (weight) also will be more.
SI unit for mass is “Kilogram” (Kg)
Force acting on the object due to gravity is called as weight. Earth has some attractive force to attract the objects towards its centre, This force accelerates the object towards centre of the earth at the rate of 9.8 m/s² (Approximately) if unopposed by any other object.
Weight changes with respect to gravity.
Gravity in earth is not same at all places but usually in calculations people often take acceleration due to gravity as 9.8 m/s² approximately.
The weight of the object is directly proportional to gravity since mass remains constant.
If the gravity becomes zero then weight of the object also will become zero.
SI unit for weight is “Newton” (N)