✔ 最佳答案
If Jupiter is made up of 100% gas, and you remove half of that gas, the mass and force of its gravity will be halved. It doesn't matter that the gasses are floating around. Technically, the Earth's atmosphere contributes to it's gravitational pull on distant objects like the moon. If you are on the surface, there is (very very small) pull from the atmosphere above you, and from the atmosphere on the other side of the earth, so they mostly cancel each other. From an external point of view, all the gases or solids just contribute to the total mass.
I'm not sure if Jupiter has a surface, but I suppose if it did and you stood on that surface and removed all the gas above you, the gravitational force on you would not change.