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]

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 $\times$ 10^$-$10 m. The value of x is ___________.

[Given hc = 1242 eV nm]