Question 397: Atoms & Nuclei

Question

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 $$	imes$$ 10$$-$$10 m. The value of x is ___________.
[Given hc = 1242 eV nm]

Accepted Answer

E(in eV) = 13.6 $$	imes$$ 9$$\left( {1 - {1 \over 9}} ight)$$
= 13.6 $$	imes$$ 8 eV
$$\Rightarrow$$ $$\lambda  = {{12420} \over {13.6 	imes 8}}\mathop A\limits^o $$
= 114.15 $$\mathop A\limits^o $$

Atoms & Nuclei

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]

Choose the correct answer: