How do you calculate the wavelength of an electromagnetic wave?

What is the wavelength of a wave that has a frequency of 1Hz & travels at 300,000 km/s ? Since the speed of the wave is 300,000 km/s, an electric charge oscillating once per second (1Hz) will produce a wave with a wavelength of 300,000 Km.

∴ The wavelength of light waves if their frequency is 5 × Hz is 0.60 micro meter .

How to calculate wavelength

Wavelength Calculator: Calculating wavelength of radio waves