1) Frequency: [tex]7.06\cdot 10^{14} Hz[/tex]
The frequency of electromagnetic radiation is given by:
[tex]f=\frac{c}{\lambda}[/tex]
where
[tex]c = 3 \cdot 10^8 m/s[/tex] is the speed of light
[tex]\lambda[/tex] is the wavelength
In this case, the wavelength of the radiation is
[tex]\lambda=425 nm=425\cdot 10^{-9} m[/tex]
Therefore the frequency is
[tex]f=\frac{3\cdot 10^8 m/s}{425 \cdot 10^{-9} m}=7.06\cdot 10^{14} Hz[/tex]
2) Period: [tex]1.42\cdot 10^{-15} s[/tex]
The period is equal to the reciprocal of the frequency of the wave:
[tex]T=\frac{1}{f}[/tex]
Using the frequency we found previously, [tex]f=7.06\cdot 10^{14} Hz[/tex], we find:
[tex]T=\frac{1}{7.06\cdot 10^{14} Hz}=1.42\cdot 10^{-15} s[/tex]
