Atomic Mass Worksheet
A Grade 12 Chemistry worksheet on atomic mass, isotopes, and calculations.
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Atomic Mass Worksheet
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Read each question carefully and provide your answers in the space provided. Show all your work for calculation questions.
1. Which of the following best describes the atomic mass of an element?
The total number of protons and electrons in an atom.
The weighted average of the masses of all naturally occurring isotopes of that element.
The mass of a single proton in an atom.
The sum of the protons and neutrons in the most abundant isotope.
2. An isotope of an element has a different number of:
protons
electrons
neutrons
atomic number
3. The unit used to express atomic mass is the (amu).
4. The number of determines the identity of an element.
5. Elements with the same number of protons but different numbers of neutrons are called .
6. Explain why the atomic mass of an element is usually not a whole number.
7. Naturally occurring boron consists of two isotopes: boron-10 (10.013 amu) and boron-11 (11.009 amu). Given that the atomic mass of boron is 10.811 amu, calculate the natural abundance of each isotope.
8. All atoms of a given element have the same atomic mass.
True
False