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QJEEM22Ph761d: JEE Main 2022 Physics - Class 12 JEEM22Ph761d Solution: A beam of monochromatic light is used to excite the electron in …

A beam of monochromatic light is used to excite the electron in Li+ + from the first orbit to the third orbit. The wavelength of monochromatic light is found to be x ×\times 10 −- 10 m. The value of x is ___________.

[Given hc = 1242 eV nm]

Step-by-Step Verified Solution

E(in eV) = 13.6 ×\times 9 (1−19)\left( {1 - {1 \over 9}} \right)

= 13.6 ×\times 8 eV

⇒\Rightarrow λ=1242013.6×8Ao\lambda = {{12420} \over {13.6 \times 8}}\mathop A\limits^o

= 114.15 Ao\mathop A\limits^o

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