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

Explanation

Given that `c=3xx10^(8)ms^(-1),lambda=4800Å=4800xx10^(-10)m=4.8xx10^(-7)m`
Using the relation frequency `=v=(c)/(lambda)=(3xx10^(8)ms^(-1))/(4.8xx10^(-7)m)=6.25xx10^(14)s^(-1)or 6.25xx10^(14)Hz`
 `therefore bar(upsilon)=(1)/(lambda)=(1)/(4.8xx10^(-7)m)=2.0833xx10^(6)m^(-1)`
Thus frequency of blue light is `6.25 xx 10^(14) Hz`. Wave number of blue light is `2.0833xx10^(6)m^(-1)`