The proportion of the mass of one element to that of another
element is a mass

yes. but next time try to ask well and clear understood questions

They experience weightlessness not because of a lack of gravity but because the ISS, and they, are orbiting Earth in constant free fall. They’re falling toward Earth and moving forward at about the same velocity. Because the downward and forward forces are nearly equal, the astronauts are not pulled in any specific direction, so they float.