Answer:
For and object to sink, it must have more density than the liquid in which it is placed. For example, if you have a glass of water and a metal spoon, the spoon will sink because it is both heavier than the water, therefore having more density.
A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral atom contains a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force. Atomic hydrogen constitutes about 75% of the baryonic mass of the universe.