Question: what type of electromagnetic radiation is 494 nm?
Answer: Visible light has a wavelength range from ~400 nm to ~700 nm. Violet light has a wavelength of ~400 nm, and a frequency of ~7.5*1014 Hz. Red light has a wavelength of ~700 nm, and a frequency of ~4.3*1014 Hz. Visible light makes up just a small part of the full electromagnetic spectrum.