Question

Atomic weights of two elements $P$ and $Q$ are $60$ and $120$ respectively, If $'x'$ gram of $P$ contains $y$ atoms, the number of atoms present in $2x$ grams of $Q$ is

• A. $0.5 \,y$
• B. $0.25 \,y$
• C. $y$
• D. $2\,y$

Answer 1

Answer: (C)

$y$

Answer 2

$60 \,g$ of $P$ contains $N_0$ atoms, So $x\, g$ of $P$ contains $\frac{N_{0}\cdot x}{60}$ atoms $= y$ $120\, g$ of $Q$ contains $N_0$ atoms, so $2x\, g$ of $Q$ contains $\frac{N_{0}\cdot2x}{120} =\frac{N_{0}\cdot x}{60} = y$