The wavelength of each of a photon and an electron is 1.00 nm. Find their (a) momentum and (b) energy.

Explanation

(a) Momentum, `p = (h)/(lamda)`
or, `p = (6.626 xx 10^(-34))/(1 xx 10^(-9)) = 6.626 xx 10^(-25) kg. m.s^(-1)`
(b) Energy of photon,
`E = (hc)/(lamda) = (6.626 xx 10^(-34) xx 3 xx 10^(8))/(10^(-9)) = 1.24 keV`
Kinetic energy of electron
`= (1)/(2) mv^(2) = (p^(2))/(2m) = ((6.626 xx 10^(-25))^(2))/(2 xx 9.1 xx 10^(-31))J = 1.51 eV`