Structure Of Atom Question 7
Question 7 - 29 January - Shift 2
Assume that the radius of the first Bohr orbit of hydrogen atom is $0.6 \stackrel{o}{A} $. The radius of the third Bohr orbit of $He^{+}$is picometer. (Nearest Integer)
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Answer: (270)
Solution:
Formula: Bohr’s Radius of Hydrogen like Atoms
$ \begin{aligned} r & \propto \frac{n^{2}}{Z} \\ r _{He^{+}} & =r_H \times \frac{n^{2}}{Z} \\ r _{He^{+}} & =0.6 \times \frac{(3)^{2}}{2} \\ & =2.7 \stackrel{o}{A} \\ r _{He^{+}} & =270 pm \end{aligned} $
