Question #8c246

1 Answer
Dec 13, 2016

Atomic number, Z = 1.


The atomic number of an element is the number of protons one of its atom contains.
One neutral atom of Hydrogen contains one electron, one proton and 0,1,2 or 3 neutrons depending on which isotope it is.

Fact: Even though Hydrogen is so small, it constitutes 75% of the elemental mass of the whole universe!