The wavelength of a probe is roughly a measure of the size of structure that it can probe in some detail. The quarks structure of photons and neutrons appears at the minute length -scale of `10^(-15)m` or less. This structure was first probed in early 1970's using high energy electron beam produced by a linear accelerator at Stanford's USA. Guess what might have been the order of energy of these electron beams (Rest mass energy of electron=0.511 eV).

Explanation

To solve the problem of estimating the energy of the electron beams used to probe the quark structure of protons and neutrons, we will follow these steps:

### Step 1: Understand the relationship between wavelength and energy
The wavelength (\( \lambda \)) of the probing electron beam is related to the momentum (\( p \)) of the electron by the de Broglie relation:
\[ p = \frac{h}{\lambda} \]
where \( h \) is Planck's constant (\( 6.626 \times 10^{-34} \, \text{Js} \)).
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