Energy of an electron in the n-th orbit of H-atom, `E_(n)=(-2.17xx10^(-11))/(n^(2))erg`. How much energy is required to remove the electron from its second orbit? Also calculate the wavelength of the light used for this process?

Explanation

`DeltaE=((-2.17xx10^(-11))/(alpha^(2)))-((-2.17xx10^(-11))/(2^(2)))`
`=0+5.42xx10^(-12)erg=5.42xx10^(-12)erg`
`lamda=(hc)/(DeltaE)=((6.626xx10^(-27))xx(3xx10^(10)))/(5.42xx10^(-12))=3.7xx10^(-5)cm`