Answer:
[tex]\large \boxed{2.404 \times 10^{17}\text{ Hz}}[/tex]
Explanation:
The formula relating the frequency (f) and wavelength (λ) is
fλ = c
1. Convert the wavelength to metres
[tex]\lambda = 1.247 \times 10^{-7}\text{ cm} \times \dfrac{\text{1 m}}{\text{100 cm }} = 1.247 \times 10^{-9}\text{ m}[/tex]
2. Calculate the frequency
[tex]\begin{array}{rcl}f \times 1.247 \times 10^{-9}\text{ m}& =& 2.998 \times 10^{8} \text{ m$\cdot $s$^{-1}$}\\f & = & \dfrac{2.998 \times 10^{8} \text{ s$^{-1}$}}{1.247 \times 10^{-9}}\\\\& = &2.404 \times 10^{17}\text{ Hz}\\\end{array}\\\text{The frequency of the light is $\large \boxed{\mathbf{2.404 \times 10^{17}}\textbf{ Hz}}$}[/tex]
