The wavelength of a blue light is 4800 Å. Calculate the frequency and wave number of this light.

Explanation

Given that `c = 3 xx 10^(8) ms^(-1)`
`lambda = 4800 Å = 4800 xx 10^(-10)m = 4.8 xx 10^(-7) m`
V = frequency = ?
Using the relation `v = (c)/(lambda) = (3 xx 10^(8))/(4.8 xx 10^(-7)m)`
`= 6.25 xx 10^(14)s^(-1)` or `6.25 xx 10^(14) Hz`
The wave number is the reciprocal of wavelength `= bar(v) = (1)/(lambda) = (1)/(4.8 xx 10^(-7)m) = 2.0833 xx 10^(6) m^(-1)`
Thus frequency of blur light is `6.25 xx 10^(14) Hz`
Wave number of blue light is `2.0833 xx 10^(6) m^(-1)`