Answer
See explanation.
Work Step by Step
The energy decrease equals the energy of the emitted photon. Calculate the wavelength of the photon.
a. $$E= hf=h\frac{c}{\lambda} $$
$$\lambda =\frac{hc}{E}=\frac{1.24\times10^{-6}eV\cdot m}{0.198eV}=6.26\times10^{-6}m$$
This radiation is in the infrared.
b. $$E= hf=h\frac{c}{\lambda} $$
$$\lambda =\frac{hc}{E}=\frac{1.24\times10^{-6}eV\cdot m}{7.80eV}=1.59\times10^{-7}m$$
This radiation is in the uv region.
c. $$E= hf=h\frac{c}{\lambda} $$
$$\lambda =\frac{hc}{E}=\frac{1.24\times10^{-6}eV\cdot m}{0.00480eV}=2.58\times10^{-4}m$$
This radiation is in the microwave region.
