Full Idea
Particles obeying the laws of quantum mechanics have wave-like properties - moving as a quantum wave-function, spread out in space, with wavelengths that get shorter as their energy increases.
Gist of Idea
Particles are spread out, with wave-like properties, and higher energy shortens the wavelength
Source
New Scientist writers (Why the Universe Exists [2017], 02)
Book Reference
New Scientist writers: 'Why the Universe Exists' [John Murray 2017], p.31
A Reaction
Thus X-rays are dangerous, but long wave radio is not. De Broglie's equation.