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Isotopes

Q. Which of the following represent isotopes? A. 32-X B. 32-X C. 31-X D. 34-X a) A and B b) A and C c) A and D d) C and D

Solved • Jan 29, 2020

Isotopes

Q. Cerium has four naturally occurring isotopes, listed in the table below. One isotope of cerium is far more abundant than any of the others. Determine the number of neutrons for each isotope and identify which isotope is the most abundant. Isotope Isotope mass (amu) 136Ce 135.907 138Ce 137.906 140Ce 139.905 142Ce 141.909 A:What is the number of neutrons in 136Ce? B:What is the number of neutrons in 138Ce? C:What is the number of neutrons in 140Ce? D:What is the number of neutrons in 142Ce?

Solved • Jan 29, 2020

Isotopes

Q. This exercise will lead you to verify that the average atomic mass of magnesium is 24.31 amu, based on the following information: The average atomic mass is the weighted average of the atomic masses of all isotopes. atomic mass = Σ atomic mass x fractional abundance What is the fractional abundance of 24-Mg?

Solved • Jan 24, 2020

Isotopes

Q. The following table presents the abundances and masses of the isotopes of zirconium. What is the atomic weight of zirconium?

Solved • Jan 24, 2020

Isotopes

Q. The element rubidium has an atomic weight of 85.47 amu. There are only two isotopes of rubidium, 85-Rb with a mass of 84.911789 amu and 87-Rb with a mass of 86.909183 amu. What are the percent isotopic abundances of rubidium? (Enter unrounded answers.)

Solved • Jan 24, 2020

Isotopes

Q. The element thallium, used in thallium sulfide photocells, has an atomic mass of 204.4 amu. There are only two isotopes of 203-Tl with a mass of 202.9723 amu and 205-Tl with a mass of 204.9744 amu. What is the percentage abundance of each of these two isotopes?

Solved • Jan 24, 2020

Isotopes

Q. This exercise will lead you to verify that the average atomic mass of magnesium is 24.31 amu, based on the following information: What is the sum of these contributions? Report your answer to two decimal places. Mass contribution of 24-Mg = 18.946 amu Mass contribution of 25-Mg = 2.499 amu Mass contribution of 26-Mg = 2.861 amu

Solved • Jan 24, 2020