Percent Abundance of Isotopes
Explore the concepts of isotopes, atomic mass, and how to calculate percent abundance in this Grade 9 science worksheet.
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Percent Abundance of Isotopes
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Read each question carefully and answer to the best of your ability. Show all your work for calculation problems.
1. What distinguishes one isotope of an element from another?
Number of protons
Number of electrons
Number of neutrons
Atomic number
2. The atomic mass listed on the periodic table is the:
Mass of the most common isotope
Mass of a single proton
Weighted average of all naturally occurring isotopes
Total mass of protons and electrons
3. Isotopes are atoms of the same element that have different numbers of , leading to different .
4. The abundance of an isotope is usually expressed as a .
5. Explain how the average atomic mass of an element is calculated from the masses and percent abundances of its isotopes.
6. All atoms of a given element have the same atomic mass.
True
False
7. The atomic number changes when an element forms an isotope.
True
False
8. Element X has two naturally occurring isotopes. Isotope X-35 has an atomic mass of 34.968 amu and a percent abundance of 75.77%. Isotope X-37 has an atomic mass of 36.966 amu and a percent abundance of 24.23%. Calculate the average atomic mass of Element X. Show all your work.