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Verbal·Expression of Ideas·Rhetorical Synthesis
easy
While researching a topic, a student has taken the following notes:
  • Element abundance is a relative measure of the occurrence of a chemical element in a given environment.
  • An element’s relative abundance can be expressed as a mass fraction, mole fraction, or volume fraction.
  • Mass fraction is the ratio of an element’s mass to the combined mass of all elements in a given environment.
  • The mass fraction of calcium (Ca) is 17,100 parts per million (ppm), or 1.71%, on Earth.
  • The mass fraction of potassium (K) is 160 ppm, or 0.016%, on Earth.
The student wants to specify an element’s relative abundance on Earth. Which choice most effectively uses relevant information from the notes to accomplish this goal?
A
Mass fraction, mole fraction, and volume fraction can all be used to express an element’s relative abundance in a given environment.
B
Expressed as a mass fraction, the relative abundance of potassium on Earth is 160 ppm, or 0.016%.
C
The relative abundance of the element potassium on Earth can be expressed in three different ways.
D
On Earth, the mass fraction of potassium is greater than that of calcium.