Question

The de-Broglie wavelength associated with a hydrogen atom moving with a thermal velocity of 3 km/s will be

• A. 1 Å
• B. 0.66 Å
• C. 6.6 Å
• D. 66 Å

Answer 1

Answer: (B)

0.66 Å

Answer 2

By using $\lambda = \frac{h}{mv_{rms}}$

⇒ $\lambda = \frac{6.6 \times 10^{- 34}}{2 \times 1.67 \times 10^{- 27} \times 3 \times 10^{3}} = 0.66Å$