The De- Broglie wavelength of an electron having 80eV energy is nearly
`(1ev=1.6xx106(-19)J)`
Mass of the electron `=9xx10^(-31)kg`Planck 's constant `=6.6xx10^(-34)J-s`

Options

A. 140Å
B. 0.14Å
C. 14Å
D. 1.4Å

Answer

D

Explanation

Energy ,K.E=80eV
Mass of the electron ,`m=9xx10^-31kg`Planck's constant `,h=6.6xx10^(-34)J`The expression fpr De - Broglie wavelengh is given as,`lamda=(h)/sqrt(2m(KE))`
`(6.6xx10^(-34))/sqrt(2xx9xx10^(-31)xx(80xx1.6xx10^(-19))`
`(therefore1eV=1.6xx10^(-19)J)`
`1.4xx10^(-10)m`
`therefore =1.4Å)`