Question

In an excited state of hydrogen like atom an electron has a total energy of –3.4 eV. If the kinetic energy of the electron is E and its de Broglie wavelength l, then–

• A. E = 6.8 eV ,l ~ 6.6 × 10^–10m
• B. E = 3.4eV, l ~ 6.6 × 10^–10 m
• C. E = 3.4 eV, l ~ 6.6 × 10^–11 m
• D. E = 6.8 eV, l ~ 6.6 × 10^–11 m

Answer 1

Answer: (B)

E = 3.4eV, l ~ 6.6 × 10^–10 m

Answer 2

l = $\frac{h}{\sqrt{2mE}}$, l = $\frac{12.27}{\sqrt{V}}Å$