Question

energy of an electron is given by equal to minus 2.2 78 into 10 to the power minus 18 June Z Square by n square wavelength of light required to excite an electron in an hydrogen atom from level and equal to 12 level and equal to 2 will be​

Answer 1

Answer : The wavelength of light required to excite an electron in an hydrogen atom from level and equal to 1 level and equal to 2 will be​, $1.235\times 10^{-7}m$

Explanation :

$\Delta E=E_2-E_1$

$\frac{hc}{\lambda}=[-2.278\times 10^{-18}\frac{Z^2}{n_1^2}]-[-2.278\times 10^{-18}\frac{Z^2}{n_2^2}]$

$\lambda=\frac{hc}{[-2.278\times 10^{-18}\frac{Z^2}{n_1^2}]-[-2.278\times 10^{-18}\frac{Z^2}{n_2^2}]}$          .........(1)

where,

$\lambda$ = wavelength of light = ?

h = Planck's constant = $6.626\times 10^{-34}Js$

c = speed of light = $3\times 10^8m/s$

Z = atomic number of hydrogen = 1

n = number of energy level

Now put all the given values in equation 1, we get:

$\lambda=\frac{(6.626\times 10^{-34})\times (3\times 10^8)}{[-2.278\times 10^{-18}\frac{1^2}{(2)^2}]-[-2.278\times 10^{-18}\frac{1^2}{(1)^2}]}$

$\lambda=1.235\times 10^{-7}m$

Therefore, the wavelength of light required to excite an electron in an hydrogen atom from level and equal to 1 level and equal to 2 will be​, $1.235\times 10^{-7}m$

Answer 2

1.235 × 10^-7 m

hope this will help you