Hey aman,
If we take an atom from chemical element hydrogen then that atom is hydrogen atom.
It is electrically neutral, it contains Single positively charged proton and a single negatively electron which is bound to the nucleus by the Coulomb force .
It contains constitutes about 75 percent of the baryonic mass of the universe
Hope it helped you!

Hello Student :

Hydrogen is the lightest gaseous element. It has one electron, one proton and no neutrons.

Here are some points regarding hydrogen atom :

• Its position in periodic table is uncertain, represents halogens as well as alkali metals.
• Its ionization energy is very high
• Compounds of hydrogen are predominantly covalent
• Hydrogen is the most abundant element is universe.
• Isotopes are protium, deuterium and tritium.Only tritium is radioactive.