Question

A moving electron has `5 xx 10^(-25) J `of kinetic energy .What is the de Broglie wavelength ?

Answer 1

Mass of the electron `(m) = 9.1 xx 10^(-31)kg`
`KE = (1)/(2) mv^(2) = 5 xx 10^(-15) J`
`lambda = (h)/(sqrt(2m xx KE)) = (6.626 xx 10^(-34))/((2 xx 9.1 xx 10^(-31) xx 5 xx 10^(-25))^(1//2)) = 6.95 xx 10^(-7) m`