Answer
a. $2.47\times10^{-19}J=1.54eV$.
b. 804 nm.
Work Step by Step
a. $E =pc =2.47\times10^{-19}J=1.54eV$.
b.
$$\lambda = \frac{h}{p}$$
$$=\frac{6.626\times10^{-34}J \cdot s}{8.24\times10^{-28}kg \cdot m/s }= 8.04\times10^{-7}m$$
This wavelength is a little longer than that of red light. It is in the infrared portion of the electromagnetic spectrum.
