Question

Element Z has 2 natural isotopes. One isotope has a mass of 15.0amu and has a relative abundance of 30%. The other isotope has a mass of 16.0amu and has a relative abundance of 70%. Estimate the average atomic mass for this element to one decimal place.

Answer 1

Answer:

The answer to your question is 15.7 amu

Explanation:

                          Abundance               Mass

Isotope 1                30%                         15

Isotope 2               70%                          16

Average atomic mass = (Abundance isotope 1 x abundance) +

                                       (Abundance isotope 2 x abundance)

Substitution

Average atomic mass =  (0.30 x 15) + (0.70 x 16)

Simplify

Average atomic mass = 4.5 + 11.2

Result

Average atomic mass = 15.7 amu