Question

Calculate the atomic mass of titanium. The five titanium isotopes have atomic masses and relative abundances of 45.953 amu (8.00%), 46.952 amu (7.30%), 47.948 amu (73.80%), 48.948 amu (5.50%), and 49.945 amu (5.40%).

Answer 1

The atomic mass of titanium is 47.88 u.

The average atomic mass of Ti is the weighted average of the atomic masses of its isotopes.

We multiply the atomic mass of each isotope by a number representing its relative importance (i.e., its % abundance).

Thus,  

0.0800 × 45.953 u =  3.676 u

0.0730 × 46.952 u =  3.427 u

0.7380 × 47.948 u = 35.386 u

0.0550 × 48.948 u =  2.692 u

0.0540 × 49.945 u =  2.697 u

_________TOTAL = 47.88 u