Per NCERT Class 11 Chemistry, what is the ATOMIC MASS UNIT (u) — used to express atomic masses?
AExactly 1/12 the mass of one atom of ¹²C (carbon-12)
BMass of one oxygen atom
CMass of one hydrogen atom
DMass of one electron
Answer & Solution
Correct answer: A. Exactly 1/12 the mass of one atom of ¹²C (carbon-12)
Per NCERT §1.7.1, 1 u = 1/12 mass of a ¹²C atom. The other options don't define the atomic mass unit.
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