To find the frequency of the wave, we can use the formula that relates the speed of light, the wavelength, and the frequency:
[tex]\[ \text{Frequency} = \frac{\text{Speed of Light}}{\text{Wavelength}} \][/tex]
Given:
- The speed of light, [tex]\( c = 3.0 \times 10^8 \)[/tex] meters/second
- The wavelength, [tex]\( \lambda = 7.0 \times 10^{-7} \)[/tex] meters
Plugging the values into the formula, we get:
[tex]\[ \text{Frequency} = \frac{3.0 \times 10^8 \, \text{m/s}}{7.0 \times 10^{-7} \, \text{m}} \][/tex]
By dividing these numbers, we find:
[tex]\[ \text{Frequency} = \frac{3.0 \times 10^8}{7.0 \times 10^{-7}} \][/tex]
This calculation yields:
[tex]\[ \text{Frequency} = 4.285714285714286 \times 10^{14} \, \text{Hz} \][/tex]
This can be approximated to:
[tex]\[ \text{Frequency} \approx 4.3 \times 10^{14} \, \text{Hz} \][/tex]
Thus, the correct answer is:
B. [tex]\( 4.3 \times 10^{14} \)[/tex] hertz