39.4k views
1 vote
An element consists of two naturally occurring isotopes with the following masses and abundances. what is the atomic mass of the element?

isotope 1: 68.928 amu, 60.11%
isotope 2: 70.925 amu, 39.89%

User Fahri
by
8.1k points

1 Answer

3 votes

Final answer:

To find the atomic mass of an element with two isotopes, multiply the mass of each isotope by its respective abundance, expressed as a decimal, then sum the results. The atomic mass of this element, rounded to two decimal places, is 69.74 amu.

Step-by-step explanation:

The atomic mass of the element with its two naturally occurring isotopes is calculated by multiplying the mass of each isotope with its relative abundance (expressed as a fraction), and then adding the products together. The formula for this calculation is:

Atomic mass = (fractional abundance of isotope 1 × mass of isotope 1) + (fractional abundance of isotope 2 × mass of isotope 2)

In this case:

  • Atomic mass = (0.6011 × 68.928 amu) + (0.3989 × 70.925 amu)
  • Atomic mass = (41.4299768 amu) + (28.306575 amu)
  • Atomic mass = 69.7365518 amu

Therefore, the average atomic mass of the element is approximately 69.74 amu.

User Feeeper
by
8.2k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.