Weight and Mass can be very confusing, but very simply:
Mass is a measure of how much matter an object is made up of. Mass remains constant. The mass of an object on the moon is the same as on Earth.
The weight of an object depends on gravity. There’s less gravity on the moon so the same object weights less on the moon than on Earth.
Mass and Weight Facts
Mass cannot be zero. Everything has mass.
Gravity has no effect on the mass of an object.
Mass is often measured in grams, kilograms and milligrams.
Your weight depends on where you are in the universe. The stronger the gravitational pull the more you weigh!
Weight is measuring in Newtons.
Weight W = Mass M x Gravitational Acceleration g
W = mg
How much would you weigh on Jupiter?
Jupiter’s gravitational pull is 2.4 that of Earth, so you would weight 2.4 times more on Jupiter than on Earth.
How much would you weigh on the Moon?
The gravity on the moon is only 16.5% of that on Earth, so you would weigh a fair bit less on the moon. If you weigh 50kg on Earth you’d only weigh 8.3kg on the moon!!
This very cool interplanetary weight calculator on the Exploratorium website works out on your weight on all the planets and some stars too!
Heavy objects are usually very dense. One very cool way to demonstrate density is by making a density column.