Question

Calculate the radius of the second orbit of He⁺.

Options

• 52.9 pm

• 105.8 pm

• 158.7 pm

• 211.6 pm

Answer 1

105.8 pm

Explanation:

\[\mathrm{r_n=\frac{52.9\times(n)^2}{Z}~pm}\]

He⁺ is a hydrogen-like species having Z = 2. 

Radius of the second orbit of He⁺

\[\mathrm{r}_{2}=\frac{52.9\times\left(2\right)^{2}}{2}\mathrm{pm}\]

∴ r₂ = 105.8 pm