The wavelength of light from the spectral emission line of sodium is 589 nm . Find the kinetic energy at which
(a) an electron and
(b) a neutron would have the same de Broglie wavelength.

Explanation

To find the kinetic energy at which an electron and a neutron would have the same de Broglie wavelength of 589 nm, we can follow these steps:

### Step 1: Convert Wavelength to Meters
The given wavelength of light from the spectral emission line of sodium is 589 nm. We need to convert this to meters.
\[ \lambda = 589 \, \text{nm} = 589 \times 10^{-9} \, \text{m} \]

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