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

Explanation

Given that `c = 3 xx 10^(8)ms^(-1)`
`lambda=4800Å=4800xx10^(-10)m=4.8xx10^(-7)m`
`"v = frequency = ? "`
`"Using the relation  "upsilon=(c )/(lambda)=(3xx10^(8))/(4.8xx10^(-7)m)`
`=6.25xx10^(14)s^(-1) or 6.25xx10^(14)Hz`
`"The wave number is the reciprocal of  wavelength "=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  umber of blue light is "2.0833 xx 10^(6) ml`