In: Chemistry
A hypothetical element consists of two isotopes of masses 70.95 amu and 72.95 amu with abundances of 30.9% and 69.1%, respectively. What is the average atomic mass of this element?
isotopes of masses : m1= 70.95 amu
m2 = 72.95 amu
abundances : A1 = 30.9 % = 0.309
A2 = 69.1% = 0.691
average atomic mass = ( atomic mass of isotope 1 x abundance 1 + atomic mass of isotope 2 x abundance 2 )
= (70.95 x 0.309 + 72.95 x 0.691)
= 72.33 amu
average atomic mass = 72.33 amu