Easy MCQ +4 / -1 PYQ · JEE Mains 2023

The radius of the $\mathrm{2^{nd}}$ orbit of $\mathrm{Li^{2+}}$ is $x$. The expected radius of the $\mathrm{3^{rd}}$ orbit of $\mathrm{Be^{3+}}$ is

  1. A $\frac{16}{27}x$
  2. B $\frac{4}{9}x$
  3. C $\frac{9}{4}x$
  4. D $\frac{27}{16}x$ Correct answer

Solution

$r_{\mathrm{Li}^{+}}=r_{0} \times \frac{2^{2}}{3}=x \Rightarrow r_{0}=\frac{3 x}{4}$ <br/><br/> $\mathrm{r}_{\mathrm{Be}^{3+}}=\mathrm{r}_{0} \times \frac{3^{2}}{4}$ <br/><br/> $r_{\mathrm{Be}^{3+}}=\frac{3 \mathrm{x}}{4} \times \frac{3^{2}}{4}=\frac{27 \mathrm{x}}{16}$

About this question

Subject: Chemistry · Chapter: Atomic Structure · Topic: Bohr's Model

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