Question

Electron has energy of 100 eV what will be its wavelength

• A. $1.2\mathring{A}$
• B. $10\mathring{A}$
• C. $100\mathring{A}$
• D. $1\mathring{A}$

Answer 1

The correct option is A $1.2\mathring{A}$

Energy $E=100ev=100\times 1.6\times {10}^{-19}Joule$

Wavelength, $\lambda =\frac{h}{\sqrt[2]{22mE}}=\frac{6.62\times {10}^{-34}Js}{\sqrt[2]{22\times 9.1\times {10}^{-31}Kg\times 1.6\times {10}^{-17}J}}=1.226\times {10}^{-10}m=1.2Angstrom$

Option A is correct.