An electron and a photon each have a wavelength of `1.00 ` nm. Find (i) their momentum (ii) the energy of the photon and (iii) K.E of electron

Explanation

(i) Linear momentum of electron `= h/ lambda`
`= (6.625xx 10^(-34))/ (1xx 10^(-9)) `
`6.625x 10^(-25) kgms^(-1)`
Linear momentum of electron `=p_(e) = 6.626 xx 10^(-25) kgms^(-1).`
Linear momentum of photon `= h/lambda 6.626xx 10^(-25) kgms^(-1).`
(ii) Energy of photon `= (hc)/ lambda`
`=(6.626 xx10^(-34)xx 3 xx 10^(8))/10^(-9)`
`= 19.87 xx 10^(-17) J `
`= 12.42 xx 10^(2)eV`
`= 1.242` keV
(iii) K.E of photon electron `= p^(2)/ (2m)`
`= ((6.626xx10^(-25))^(2))/(2xx9.1xx 10^-31)`
`=(43.904)/(18.2)xx 10^(-19) = 2.412 xx 10^(-19)Jdiv 1.6 xx 10^(-19)`
`=1.508` eV