Answer
(a) $E = 1.86\times 10^{-6}~eV$
(b) $E = 2.76~eV$
(c) $E = 27.6~keV$
Work Step by Step
(a) We can find the energy of each photon:
$E = h~f$
$E = (6.626\times 10^{-34}~J~s)(450\times 10^6~Hz)$
$E = 2.9817\times 10^{-25}~J$
$E = (2.9817\times 10^{-25}~J)(\frac{1~eV}{1.6\times 10^{-19}~J})$
$E = 1.86\times 10^{-6}~eV$
(b) We can find the energy of each photon:
$E = \frac{h~c}{\lambda}$
$E = \frac{(6.626\times 10^{-34}~J~s)(3.0\times 10^8~m/s)}{450\times 10^{-9}~m}$
$E = 4.4173\times 10^{-19}~J$
$E = (4.4173\times 10^{-19}~J)(\frac{1~eV}{1.6\times 10^{-19}~J})$
$E = 2.76~eV$
(c) We can find the energy of each photon:
$E = \frac{h~c}{\lambda}$
$E = \frac{(6.626\times 10^{-34}~J~s)(3.0\times 10^8~m/s)}{0.045\times 10^{-9}~m}$
$E = 4.4173\times 10^{-15}~J$
$E = (4.4173\times 10^{-15}~J)(\frac{1~eV}{1.6\times 10^{-19}~J})$
$E = 2.76\times 10^4~eV$
$E = 27.6~keV$
