The mass of an electron is `9.1xx10^(-31)kg`. If its K.E. is `3.0xx10^(-25)J`, calculate its wavelength.

Explanation

Mass of an electron `(m)=9.1xx10^(-31)kg`,
`KE=(1)/(2)mv^(2)=3.0xx10^(-25)J`
`therefore`Velocity of an electron `(v)=sqrt((2xxKE)/(m))=sqrt((2xx3.0xx10^(-25)J)/(9.1xx10^(-31)kg))`
`=812m*s^(-1)`
`therefore`Wavelength of the moving electron `(lamda)=(h)/(mv)`
`=(6.626xx10^(-34)J*s)/((9.1xx10^(-31)kg)xx(812m*s^(-1)))=8.967xx10^(-7)m`\