Atomic Mass Unit — Prelims Questions

Which of the following statements correctly defines one Atomic Mass Unit (amu)?

If the atomic mass of an element is $M$ amu, what is the mass of one mole of this element in grams?

Calculate the mass of a single atom of Helium (He) in grams, given that its atomic mass is 4.0026 amu. (Given: $1,\text{amu} = 1.6605 \times 10^{-24},\text{g}$)

An element X has two isotopes: $^{20}\text{X}$ (90% abundance, mass = 19.9924 amu) and $^{22}\text{X}$ (10% abundance, mass = 21.9914 amu). What is the average atomic mass of element X?

Which of the following statements about the Atomic Mass Unit (amu) is INCORRECT?

What is the molecular mass of carbon dioxide ($CO_2$) in amu? (Given: Atomic mass of C = 12.01 amu, Atomic mass of O = 16.00 amu)