The frequency of violet light with a wavelength of 420 nm is
.
Further explanation:
Wavelength is the characteristic property of a wave. It is defined as the distance between two successive crests or troughs. A crest is that point where there is maximum displacement of the medium whereas trough is a point that has minimum displacement of the medium. It is represented by
and its SI unit is meter (m).
Frequency is defined as the number of times n event occurs in unit time. It is generally applied to waves including light, sound and radio waves. It is denoted by
and its SI unit is Hertz (Hz).
The formula to calculate the frequency of violet light is as follows:
...... (1)
Here,
c is the speed of violet light.
is the frequency of violet light.
is the wavelength of violet light.
Firstly, the wavelength is to be converted into m. The conversion factor for this is,

So the wavelength of violet light can be calculated as follows:

The value of the wavelength of violet light is
.
The value of the speed of violet light is
.
Substitute these values in equation (1).

Learn more:
1. Statement about subatomic particle: brainly.com/question/3176193
2. The energy of a photon in light: brainly.com/question/7590814
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Structure of the atom
Keywords: wavelength, frequency, 420 nm, wavelength of violet light, speed of violet light, frequency of violet light, 3*10^8 m/s, 7.14*10^16 s-1, c, distance, crest, trough.