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An electron joins a helium nucleus to fo...

An electron joins a helium nucleus to form `He^(+)`. Find the wavelength of the photon emitted in this process (in `nm`) if the electron is assumed to have no kinetic energy when it combines with nucleus. Assume Bohr's model to be applicable.

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The correct Answer is:
`22.8 nm`
Assuming Bohr's model to be apllicable to the He atom too,
Energy of electron `=-13.6xx4 eV=-54.4 eV` initial energy of electron `=0`
Energy of photon emitted `=544 eV`
`lambda=(hc)/(DeltaE)=22.8 mm`
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