Question

Calculate the energy of a quantum of light with a frequency of 4.31*10^11 kHz

Answer 1

Step-by-step explanation:

The energy of a quantum of light with frequency v is given by

`E=hv`

where h = planck's constant = 6.63 *10^-34 and v = frequency of light.

Now in our case, we are told that

`v=4.21*10^(11)*10^3Hz`

The extra 10^3 comes from the fact that we were given kilohertz (and not simply hertz).

Substituting the value of the given frequency and the Planck's constant into the above equation gives

`E=(6.63*10^(-34))*(4.21*10^(11)*10^3)`

which upon evaluating gives

`\boxed{E=2.79*10^(-19)J}`

Hence, the energy of our quantum of light is 2.79*10^-19 Joules!