Answer
Hydrogen and helium particles can reach speeds which are greater than the escape speed from the Earth, and these particles can escape from the Earth's atmosphere and fly off into space.
The escape velocity from Jupiter is significantly greater than the escape velocity from the Earth. Therefore, the hydrogen and helium particles in Jupiter's atmosphere do not move at speeds which surpass the escape velocity from Jupiter and they remain in Jupiter's atmosphere.
Work Step by Step
The average kinetic energy of gas particles in the atmosphere is equal for different types of gases. Since hydrogen and helium particles have a smaller mass, they move at a faster speed. Hydrogen and helium particles can reach speeds which are greater than the escape speed from the Earth, and these particles can escape from the Earth's atmosphere and fly off into space.
The escape velocity from Jupiter is significantly greater than the escape velocity from the Earth. Therefore, the hydrogen and helium particles in Jupiter's atmosphere do not move at speeds which surpass the escape velocity from Jupiter and they remain in Jupiter's atmosphere.
