Question

Calculate the radius of first orbit in $H{e}^{+}$ ion.

• A. $0.2645A^o$
• B. $26.45A^o$
• C. $0.2465\times {10}^{-12}$
• D. none of these

Answer 1

The correct option is A $0.2645A^o$

Bohr Radius $=\frac{R_0{n}^2}{Z}$

where, $R_0=0.529$$\mathring{A}$

Now, first orbit of $H{e}^{+}$ -> n=1,z=2.

$R=\frac{R_0}{2}$ $=0.2645$ $\mathring{A}$

$\therefore$ The radius of first orbit in $H{e}^{+}$ ion is 0.2645 $\mathring{A}$