Answer:
Red light
Explanation:
The energy emitted during an electron transition in an atom of hydrogen is given by
[tex]E=E_0 (\frac{1}{n_2^2}-\frac{1}{n_1^2})[/tex]
where
[tex]E_0 = 13.6 eV[/tex] is the energy of the lowest level
n1 and n2 are the numbers corresponding to the two levels
Here we have
n1 = 3
n2 = 2
So the energy of the emitted photon is
[tex]E=(13.6) (\frac{1}{2^2}-\frac{1}{3^2})=1.9 eV[/tex]
Converting into Joules,
[tex]E=(1.9 eV)(1.6\cdot 10^{-19} J/eV)=3.0\cdot 10^{-19} J[/tex]
And now we can find the wavelength of the emitted photon by using the equation
[tex]E=\frac{hc}{\lambda}[/tex]
where h is the Planck constant and c is the speed of light. Solving for [tex]\lambda[/tex],
[tex]\lambda=\frac{hc}{E}=\frac{(6.63\cdot 10^{-34})(3\cdot 10^8)}{3.0\cdot 10^{-19}}=6.63\cdot 10^{-7} m = 663 nm[/tex]
And this wavelength corresponds to red light.
