the wavelegth range of the visible spectrum extends from violet ( 400 nm) to red ( 750 nm). Express these wavelengths in frequencies (Hz) . (1nm =` 10 ^(-9)m`)

Explanation

using equation 2.5, frequency of violet light
`v= c/lambda=(3.00xx10^(8)ms^(-1))/(400xx10^(-9)m)`
` 7.50xx10^(14) Hz`
frequency of red light `v= c/lambda=(3.00xx10^(8)ms^(-1))/(400xx10^(-9)m)=4.00xx10^(14)Hz`
the range of visible spectrum is form `4.0xx10^(14) "to" 7.5 xx 10^(14) Hz` in terms of frequency units.