* Hydrogen is a chemical element with the symbol H and atomic number 1. It is the lightest and most abundant element in the universe.
* Sulfide is an anion (negatively charged ion) formed from sulfur, with the formula S2−. It is a component of many compounds, including hydrogen sulfide (H2S).
In simpler terms:
* Hydrogen is a single atom.
* Sulfide is a group of atoms (specifically sulfur atoms) with a negative charge.
Hydrogen sulfide is a compound made up of two hydrogen atoms bonded to one sulfur atom. It has a distinctive rotten egg smell and is highly toxic.
