contestada

Nitrogen has two isotopes. One has an atomic mass of 14.003
amu and a relative abundance of 99.63% while the other
isotope has an atomic mass of 15.000 amu and a relative
abundance of 0.37%. What is the average atomic mass for
nitrogen?
a
14.456 amu
b
14.778 amu
C 14.993 amu
d 14.007 amu