Answer:
15 pm
Explanation:
Speed of a wave is given as:
Speed = wavelength * frequency
Since electromagnetic waves move at the speed of light, we can calculate the wavelength:
Wavelength = speed/frequency
Wavelength = (3 * 10^8)/(2 * 10^19)
Wavelength = 1.5 * 10^(-11) m
In picometre, pm, wavelength the is 15 pm.