There are two isotopes of an unknown element, X-19 and X-21. The abundance of X-19 is 12.01%. a) A weighted average uses the percentages of each isotope to scale their contribution to the total mass. Each isotope's contribution is the percentage (in decimal form) multiplied by the mass of the isotope. What is the contribution (in amu) to the weighted average from the X-19 isotope, which has a mass of 19.00 amu? b) What is the percentage of the X-21 isotope? c) What is the contribution (in amu) to the weighted average from the X-21 isotope, which has a mass of 21.00 amu? d) What is the average atomic mass (in amu) of this element using four significant figures?

There are two isotopes of an unknown element, X-19 and X-21. The abundance of X-19 is 12.01%. a) A weighted average uses the percentages of each isotope to scale their contribution to the total mass. Each isotope's contribution is the percentage (in decimal form) multiplied by the mass of the isotope. What is the contribution (in amu) to the weighted average from the X-19 isotope, which has a mass of 19.00 amu? b) What is the percentage of the X-21 isotope? c) What is the contribution (in amu) to the weighted average from the X-21 isotope, which has a mass of 21.00 amu? d) What is the average atomic mass (in amu) of this element using four significant figures?

Introductory Chemistry: A Foundation

9th Edition

ISBN:9781337399425

Author:Steven S. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Donald J. DeCoste

Chapter4: Chemical Foundations: Elements, Atoms, And Ions

Section: Chapter Questions

Problem 95AP: Though the common isotope of aluminum has a mass number of 27, isotopes of aluminum have been...

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