Lifetimes of the molecules in the excited states are often measured by using pulsed radiation source of duration nearly in the nano second range . If the radiation source has the emitted during the pulse source is `2.5 xx 10^(15)` .Calculate the energy of the source .

Explanation

radiation duration `=2 ns = 2 xx 10^(9) s`
Frequency = `(1) /(" radiation period ") = (1)/( 2xx 10^(9) s)`
total = No of photon (N ) `xx ` energy of 1 photon (hv ) E = Nhv
`=(2.5 xx 10^(15) ) (1.626 xx 10^(34) J s) (5.0 xx 10^(8) s)`
`=82 .825 xx 10^(11) J`
`=8.282 xx 10^(10)J`