Mendeleev was the first scientist to arrange the element in such a periodic order but there was a mistake that he arranged in increasing order of mass.
Today we use the periodic table given by Henry Mosley where atomic no is first priority
The amount of gravity is directly proportional to the amount of mass of the objects and inversely proportional to the square of the distance between the objects. Gravity is a force that increases the velocity of falling objects - they accelerate.