Related Clues:

• Diminutive superhero (with "The")
• Symbol in the logo of 'The Big Bang Theory'
• Focus of physics
• AEC logo
• Accelerator item
• It was once thought to be smallest particle of matter
• Ion, for instance
• Very small part, it's half the alphabet
• A tiny bit acidic at first, when given to cat
• Moat (anag.)
• Half the alphabet, but still very little
• A big bell? It's very small
• For a male, it's very little
• Mite found on a moggy
• A cat scrap