proton is the name for a nuclear particle that has about the same mass as a neutron, but with a positive charge.
Moseley established a more accurate periodic table by closer determination of atomic numbers. Through the results of his measurements of the wavelengths of the X-ray spectral lines of a number of elements which showed that the ordering of the elements by atomic number.
Gravitational force -an attractive force that exists between all objects with mass; an object with mass attracts another object with mass; the magnitude of the force is directly proportional to the masses of the two objects and inversely proportional to the square of the distance between the two objects.
