Related Clues:

• + or - item
• Molecule part
• Item of interest to Niels Bohr
• Negatively charged particle
• Itty-bitty bit
• First half of the files?
• It may have an extra electron
• Physics subject
• Part of a joule
• See 41-Down
• Smashed item
• Hydrolysis atom
• Bit of energy
• Unit of work
• Tiny part