The atomic mass of Hydrogen : 1.02985
Further explanation
Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
In determining the mass of an atom, as a standard is the mass of 1 carbon-12 atom whose mass is 12 amu
An atomic mass unit = amu is a relative atomic mass of 1/12 the mass of an atom of carbon-12.
Mass atom X = mass isotope 1 . % + mass isotope 2.% ..
99.985% is hydrogen-1 and 0.015% is hydrogen-2
The atomic mass of Hydrogen :
[tex]\tt atomic~mass~H=0.99985\times 1+0.015\times 2\\\\atomic~mass~H=1.02985[/tex]
