frequency is thhe number of waves that crosses a fixed point in one second . The unit of frequency is per second.
Step 1
a) convert the energy into joules
the equivalence is
[tex]1\text{ eV=1.6*10}^{-19}\text{ Joules}[/tex]so, 5 eV, will be 5 times this amount, so
[tex]Energy=5\text{ eV=5*1.6*10}^{-19}=2.3*10^{-18}\text{ Joules}[/tex]Step 2
we also know that, Photon energy(E) is the multiplication of plank's constant (h) and frequency(v)
so
[tex]E=hv[/tex]replace and solve for frequency(v)
[tex]\begin{gathered} E=hv \\ 2.3*10^{-18}=6.63*10^{-34}*v \\ divide\text{ both sides by 6.63*10}^{-34} \\ \frac{2.3*10^{-18}}{6.63*10^{-34}}=\frac{6.63*10^{-34}*v}{6.63*10^{-34}} \\ 3.47*10^{15}=v \end{gathered}[/tex]therefore, the answer is
[tex]frequency=\text{ 3.47*10}^{15}\text{ Hz}[/tex]I hope this helps you
