Atomic Mass Worksheet
A Grade 11 Science worksheet covering atomic mass, isotopes, and calculations.
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Atomic Mass Worksheet
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Read each question carefully and answer to the best of your ability. Show all work for calculations.
1. What does the atomic mass unit (amu) primarily represent?
The mass of an electron
1/12th the mass of a carbon-12 atom
The average mass of all isotopes of an element
The number of protons in an atom
2. Which of the following best describes isotopes?
Atoms with different numbers of protons
Atoms with different numbers of electrons
Atoms of the same element with different numbers of neutrons
Atoms of different elements with the same mass number
3. The weighted average of the masses of all naturally occurring isotopes of an element is known as its .
4. The number of in an atom determines its atomic number and thus its identity as an element.
5. Explain the difference between mass number and atomic mass.
6. Chlorine has two main isotopes: chlorine-35 (mass = 34.969 amu) with an abundance of 75.77%, and chlorine-37 (mass = 36.966 amu) with an abundance of 24.23%. Calculate the average atomic mass of chlorine. Show your work.
7. All atoms of a given element have the same atomic mass.
True
False