Yellow light emitted from a sodium lamp has a wavelength ( `lambda` ) of ` 580 nm`. Calculate the frequency (v). Wave number and energy of yellow light photon .

Explanation

Wavelength of yellow light `(lambda) = 580 nm`
`" " = 580 xx 10^(-9) m`
`" " [1 nm = 10^(-9)m]`
We know that frequency (v) is related to wavelength as :
`lambda xx v = c "or" v = c/(lambda)`
where, c, velocity of light = `3.0 xx 10^(8) ms^(-1)`
`:. " " v = (3.0 xx 10^8 ms^(-1))/(580 xx 10^(-9) m)`
`" " = 5.17 xx 10^(14) s^(-1)`
Again, wave number , `bar(v) = 1/(lambda)`
`bar(v) = (1)/(580 xx 10^(-9) m)`
`= 1.72 xx 10^(6) m^(-1)`
Therefore, frequency = `5.17 xx 10^(14) s^(-1)`
and wave number `= 1.72 xx 10^(6) m^(-1)` .