Question

Find the radius of $Be ^{3+}$ in the ground state assuming Bohr model to be applicable.

Answer 1

SOLUTION : The radius of $n^{t h}$ orbit of hydrogen-like ions, $r_{n}=0.529 \times \frac{n^{2}}{Z} Å$

Where $0.529 Å=$ radius of the hydrogen atom in the ground state $Z$ for $B e^{3+}=4$

Radius of $Be^{3+}$ in the ground state $n=1$ is equal to $\frac{0.529 \times 1^{2}}{4-} Å= 0 \cdot 132 Å$.