Radius of the first excited state of Helium ion is given as : $\mathrm{a}_0 \rightarrow$ radius of first stationary state of hydrogen atom.
Solution
<p>$r_n = \frac{n^2\, a_0}{Z}$</p>
<p>For the helium ion, which is hydrogen-like with a nuclear charge of $Z = 2$, the first excited state corresponds to $n = 2$. Substituting these values:</p>
<p>$r_2 = \frac{(2)^2\, a_0}{2} = \frac{4\, a_0}{2} = 2\, a_0$</p>
<p>Thus, the radius of the first excited state of the helium ion is $2\, a_0$.</p>
About this question
Subject: Chemistry · Chapter: Atomic Structure · Topic: Bohr's Model
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