| THOMSON | J. J. -; discoverer of the electron whose son George co-discovered the diffraction of electrons by crystals (7) |
| LAUE | Max von -; physicist awarded a Nobel Prize for his discovery of the diffraction of X-rays by crystals (4) |
| FRANCISCRICK | Nobelist who co-discovered the structure of DNA |
| ABELSON | Philip --, American physicist who co-discovered the element neptunium (7) |
| SUNDOG | Depicted in a drawing by John Sell Cotman, a parhelion on the solar halo as a result of diffraction of light by ice crystals in the atmosphere (6) |
| DIRAC | Nobel Prize-winning theoretical physicist who described the properties of the electron and predicted |
| CORONA | Aureola of the sun or moon caused by diffraction by cloud droplets or ice crystals; the trumpet of a daffodil or other narcissus; or, a circular chandelier in a church (6) |
| NEON | One of the elements co-discovered by Sir William Ramsay along with argon, helium, krypton and xenon |
| FAIRTHORPE | Maker of the Electron Minor (10) |
| NEGATRON | Former name of the electron |
| MUON | Unstable subatomic particle of the lepton class similar to the electron but approximately 207 times heavier (4) |
| SPECTRUM | The distribution of colours produced when white light is dispersed by a prism or diffraction grating (8) |
| ATOM | Basic unit of matter consisting of Rutherford's "gold foil" discovery of a tiny-massive nucleus within a cloud of electrons likened by said scientist to planets orbiting the sun (4) |
| AIRY | Light I observed in diffraction of ray (4) |
| FRINGE | A border of loose threads, tassels or twists; hair or "bangs" falling over one's brow; non-mainstream theatre; or, a bright or dark band produced by diffraction or interference of light (6) |
| BRARG | Scientist noted for X-ray diffraction who shared the 1915 Nobel Prize in Physics with his son (5) |
| VALENCE | Combining power of atoms, measured by the number of electrons gained, lost or shared when forming compounds (7) |
| NUCLEUS | Positively charged central region of an atom, composed of protons and neutrons surrounded by a cloud of electrons (7) |
| ESAKI | Japanese quantum physicist whose discovery of electron tunnelling led to his design of the tunnel diode (5) |
| IVATT | Surname of notable engineers Henry and son George (5) |
