Energy of an electron is givem by `E = - 2.178 xx 10^-18 J ((Z^2)/(n^2))`. Wavelength of light required to excited an electron in an hydrogen atom from level `n = 1` to `n = 2` will be
`(h = 6.62 xx 10^-34 Js` and `c = 3.0 xx 10^8 ms^-1`).

Options

A. `1.214xx10^(-7)m`
B. `2.816xx10^(-7)m`
C. `6.500xx10^(-7)m`
D. `8.500xx10^(-7)m`

Answer

A

Explanation

`Delta E=2.178xx10^(-18) ((1)/(I^(2))-(1)/(2^(2)))=(hc)/(lamda)`
`2.17xx10^(-18)xx(3)/(4)=(hc)/(lamda)=(6.62xx10^(-34)xx3xx10^(8))/(lamda)`
`lamda=(6.62xx10^(-34)xx3xx10^(8)xx4)/(2.17xx10^(-18)xx3)=1.214xx10^(-7)m`