Find the accelerating potential (in volts, nearest integer) needed to give an electron a de Broglie wavelength of $0.50 \overset{˚}{A}$ . Use $h = 6.626 \times 1 0^{- 34} J s$ , $m_{e} = 9.1 \times 1 0^{- 31} kg$ , $e = 1.6 \times 1 0^{- 19} C$ .

Numerical answer type, answer in V, tolerance 2.

Answer: 603.1 V

From

e V = h^{2} / (2 m_{e} λ^{2})

V = (6.626 \times 1 0^{- 34})^{2} / (2 \times 9.1 \times 1 0^{- 31} \times 1.6 \times 1 0^{- 19} \times (0.50 \times 1 0^{- 10})^{2}) = 603.1 V