Questions: Which of the following equals one atomic mass unit? A. one-twelth the mass of one carbon-12 atom B. the mass of one helium-4 atom c. the mass of one carbon-12 atom D. the mass of one electron

Solution Steps

An atomic mass unit (AMU) is a standard unit of mass that quantifies mass on an atomic or molecular scale. It is defined as one-twelfth the mass of a carbon-12 atom. This definition is used because carbon-12 is a stable isotope and provides a convenient reference point.

Let's analyze each option to determine which one matches the definition of an atomic mass unit:

• A. one-twelfth the mass of one carbon-12 atom: This matches the definition of an atomic mass unit.
• B. the mass of one helium-4 atom: This is incorrect because a helium-4 atom has a different mass than one atomic mass unit.
• C. the mass of one carbon-12 atom: This is incorrect because one atomic mass unit is only one-twelfth of the mass of a carbon-12 atom.
• D. the mass of one electron: This is incorrect because the mass of an electron is much smaller than one atomic mass unit.

Final Answer