Answer
a) $f=9.8\times 10^{14}Hz$
b) $\lambda=306\times 10^{-9}m=306nm$
Work Step by Step
We can determine the required frequency as follows:
$E=hf$
We plug in the known values to obtain:
$6.5\times 10^{-19}J=(6.625\times 10^{-34}J.s)f$
$\implies f=\frac{6.5\times 10^{-19}J}{6.625\times 10^{-34}J.s}$
$f=9.8\times 10^{14}Hz$
Now, the wavelength can be calculated as
$\lambda=\frac{c}{f}$
We plug in the known values to obtain:
$\lambda=\frac{3\times 10^8m/s}{9.8\times 10^{14}Hz}$
$\lambda=306\times 10^{-9}m=306nm$
