Q1 / 160 · TS EAMCET 2023 (13 May Shift 1) · Chemistry

The radius of first Bohr orbit of hydrogen atom is same as that of orbit (n) of hydrogen like species X. (n) and X respectively are

  • A
    (2), $\mathrm{Li}^{2+}$
  • B
    (3), $\mathrm{Li}^{2+}$
  • Correct answer
    C
    (2), $\mathrm{Be}^{3+}$
  • D
    (2), $\mathrm{He}^{+}$

Solution

Radius of ' $n{ }^{\text {th' }}$ orbit of a hydrogen-like species is:- $$ r_n=\frac{0.529 n^2}{z} Å $$ For first orbit of hydrogen atom, $r$ $=0.529 Å$ the radii to be equal; $\mathrm{n}^2=\mathrm{z}$ $\Rightarrow \mathrm{n}=2$ for $\mathrm{Be}^{3+}$ whose $\mathrm{z}=4$ $\Rightarrow \mathrm{n}=2$ and $\mathrm{x}=\mathrm{Be}^{3+}$.

Hence, the correct answer is option: 'C'.

Relevant Questions