Related Clues:

• What's split in a fission reaction
• Thing of little matter to physicists?
• Small particle studied by Maria Goeppert Mayer
• Particle hidden in 'roma tomatoes'
• The Acorn ____’s successor became the BBC Micro in 1981
• Some anatomical bit that is very small
• Minuscule part of anatomy
• Quark's particle
• Scrap half of the letters we write?
• Particle with an orbital system
• Fission target
• Smallest thing you can split
• Tiny molecular unit
• Tiny part from a male cat
• Physics study