Q. Arrange the following in the order of increasing mass (atomic mass; O = 16, Cu = 63, N = 14) One atom of oxygen One atom of nitrogen $1 \times 10^{- 10}\$mole of oxygen $1 \times 10^{- 10}$mole of copper
A) $II < I < III < IV\$
B) $I < II < III < IV$
C) $III < II < IV < I$
D) $IV < II < III < I$
Explanation
(a)
Mass of one atom of oxygen =
$\frac{16}{6.022 \times 10^{23}} = 2.66 \times 10^{- 23}\$g
Mass of one atom of nitrogen
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ = \frac{14}{6.022 \times 10^{23}} = 2.32 \times 10^{- 23}$g
Mass of$\ 1 \times 10^{- 10}$mole of oxygen
$= 16 \times 10^{- 10}\ g$
Mass of$\ 1 \times 10^{- 10}$ mole of copper
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ = 63 \times 10^{- 10}$
Hence, masses of atoms in increasing order
II< I< III < IV
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.