Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
Bohr's radius of $2 \mathrm{nd}$ orbit of $\mathrm{Be}^{3+}$ is equal to that of
ChemistryStructure of AtomCOMEDKCOMEDK 2023
Options:
  • A 4th orbit of hydrogen
  • B 2nd orbit of $\mathrm{He}^{+}$
  • C 3 rd obit of $\mathrm{Li}^{2+}$
  • D 1st orbit of hydrogen
Solution:
2670 Upvotes Verified Answer
The correct answer is: 1st orbit of hydrogen
Bohr radius for $n$th orbit $=0.53 Å \times \frac{n^2}{Z}$
where, $Z=$ atomic number
$\therefore$ Bohr radius of 2 nd orbit of
$\mathrm{Be}^{3+}=\frac{0.53 \times(2)^3}{4}=0.53 Å$
For option (d) Bohr radius of 1st orbit of
$\mathrm{H}=\frac{0.53 \times(1)^3}{1}=0.53 Å$
Hence, Bohr's radius of $2 \mathrm{nd}$ orbit of $\mathrm{Be}^{3+}$ is equal to that of first orbit of hydrogen.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.