Grade 12 Chemistry: Relative Mass
A Grade 12 chemistry worksheet covering relative atomic mass, isotopic abundance, and calculations involving average atomic mass.
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Grade 12 Chemistry: Relative Mass
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Read each question carefully and provide your answers in the space provided. Show all your work for calculation questions.
1. What is the standard used to define the atomic mass unit (amu)?
A single atom of hydrogen-1
One-twelfth the mass of a carbon-12 atom
The average mass of an oxygen atom
The mass of a proton
2. Relative atomic mass is a weighted average of the masses of an element's , taking into account their natural .
3. The mass of one mole of a substance is called its mass, and it is numerically equal to the atomic mass in grams.
4. Explain why the atomic mass of an element listed on the periodic table is rarely a whole number.
5. Naturally occurring chlorine is 75.77% chlorine-35 (mass 34.969 amu) and 24.23% chlorine-37 (mass 36.966 amu). Calculate the average atomic mass of chlorine.
6. All isotopes of an element have the same number of protons but different numbers of neutrons.
True
False