Hydrogen
The atomic number is 1and the Maas number is 1.00794u+0.00001u
It is in period 1 and group 1
It is the lightest element on the periodic table.
Hydrogen is the most abundant chemical substance in the universe constituting roughly 75%of all baryonic mass.
Uses of hydrogen
Pumping gas and fueling cars.
Hydrogen peroxide
Hydrogen peroxide is used for cleaning cuts.
Rockets
Hydrogen is used in the rocket to go into space.