Question

Which of the following statements is/are correct?

I.
II.
Mass of 1 atom of Carbon-12 is equal to 1 amu
Mass of 4 atoms of Carbon-12 is equal to mass of 3 atoms of Oxygen-16
(A) Only I
(B) Only II
(C) Both I and II
(D) None of them
​

Answer 1

The correct statement is;

(B) Only II

Step-by-step explanation:

I) The atomic mass unit or amu which is also known as daltons which is defined as 1/12 × the mass of a carbon-12 atom, which is therefore, 1.660538921 × ⁻²⁴ grams

Therefore, the mass of 1 atom of carbon-12 = 12 amu

II) The mass of one mole of oxygen-16 is 16 grams while the mass of one mole of carbon-12 is 12 grams

The mass of 4 atoms of carbon 12 = 4 × 12 amu = 48 amu

The mass of 1 atom of oxygen-16 = 15.99491461956 amu

Therefore, the mass of 3 atoms of oxygen-16 = 3 × 15.99491461956 = 47.9847438587 amu ≈ 48 amu

Therefore only II is correct.