Related Clues:

• Participant in a collision
• Label on the first of two file drawers, often
• Fermi's unit
• Site of tiny orbits
• It may be smashed
• Nucleus + electrons
• Minute fragment
• Proton spot
• Minuscule bit
• Carbon 13, e.g.
• Wee energy source
• Certain smasher's target
• Subject for John Dalton
• Mite
• Uranium 235, for example