While finding the relative atomic mass, which of the following standard is used to compare the atomic mass of chlorine (35.5 amu)
Correct answer: C. Carbon - 12
- A. Carbon - 13
- B. Neon - 20
- C. Carbon - 12
- D. Nucleon number
Explanation
By international agreement in 1961 for determining atomic masses, carbon-12 a distinct atom of carbon was chosen as standard with its atomic mass 12.00 atomic mass unit. It is defined as 1/12 the mass of an atom of carbon-12. Masses of all other atoms are determined relative to the mass of an atom of carbon 12. Relative atomic mass equals the average mass of all the atoms in an element compared to 1/12 the mass of a carbon-12. Carbon-12 is the standard while measuring the atomic masses. Because no other nuclides other than carbon-12 have exactly whole-number masses in this scale.
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