Percent Abundance of Isotopes

Percent Abundance of Isotopes Worksheet

Read each question carefully and provide detailed answers. Show all your work for calculation problems.

1. Define isotope and explain how isotopes of the same element differ from each other.

2. The atomic mass of an element listed on the periodic table is the   atomic mass, which is a weighted average of the masses of its naturally occurring isotopes.

3. Percent abundance refers to the percentage of atoms of a natural sample of the   that are of a particular isotope.

4. Which of the following statements about isotopes is FALSE?

5. Copper has two naturally occurring isotopes: Copper-63 (atomic mass = 62.9296 amu) and Copper-65 (atomic mass = 64.9278 amu). If the average atomic mass of copper is 63.546 amu, calculate the percent abundance of each isotope.

6. An element has three isotopes with the following masses and percent abundances: Isotope 1: 27.977 amu (92.23%), Isotope 2: 28.976 amu (4.67%), Isotope 3: 29.974 amu (3.10%). Calculate the average atomic mass of this element. Identify the element.

7. All atoms of a given element have the same mass.

8. The mass number is the sum of protons and electrons in an atom.