Sure
There are planets in our solar system that have 100% liquid surfaces, why not water.
there is not water and oxygen
Boats would be unnecessary on a planet without water. if the planet didn't have any water we would all die of dehydration.
Yes, nuclear bombs can destroy most if not all human, animal, and plant life, and contaminate water supplies.
yes. an ecosystem involves plants animals and water. earth is a big ecosystem and its a planet. so it is possible
underground
Saturn is a gas planet, and if it were possible to place it in water it would float. Not sure if the rings would float, but, the planet itself would.
Ganymede is solid, as are all the moons in the solar system. However, the fact that Ganymede is a moon means that it is not a planet.
as of now no because there is no oxygen and no water ...maybe in the future though
Earth.
earth
It is not possible: Mercury does not have a frozen planet.
Its possible, even probable. It would need to be cold (not extremely, but enough for it to snow) and there would have to be water on that planet.