What are the differences between a hydrogen balloon and a helium balloon in terms of safety, buoyancy, and availability?

Hydrogen balloons are more flammable and pose a higher safety risk compared to helium balloons, which are non-flammable. Helium balloons have better buoyancy and can lift heavier loads than hydrogen balloons. Helium is more readily available and safer to use compared to hydrogen, which is more difficult to obtain and handle safely.