Answer
(a) $3.14\times10^{-19}\,J$
(b) $3.95\times10^{-19}\,J$
(c) $3.8\times10^{-15}\,J$
Work Step by Step
Using the relation $E=\frac{hc}{\lambda}$, we have
(a) $E=\frac{(6.626\times10^{-34}\,J\cdot s)(3.00\times10^{8}\,m/s)}{632.8\times10^{-9}\,m}$
$=3.14\times10^{-19}\,J$
(b) $E=\frac{(6.626\times10^{-34}\,J\cdot s)(3.00\times10^{8}\,m/s)}{503\times10^{-9}\,m}$
$=3.95\times10^{-19}\,J$
(c) $E=\frac{(6.626\times10^{-34}\,J\cdot s)(3.00\times10^{8}\,m/s)}{0.052\times10^{-9}\,m}$
$=3.8\times10^{-15}\,J$