Related Clues:

• It was once thought to be smallest particle of matter
• Ion, for instance
• Powerful agency about to take on a member of the cast
• Very small part, it's half the alphabet
• Clergyman touring a power plant
• A tiny bit acidic at first, when given to cat
• Moat (anag.)
• Half the alphabet, but still very little
• Provider of nuclear power
• It's a pile of energy
• Creator (anag.)
• A big bell? It's very small
• For a male, it's very little
• Mite found on a moggy
• A cat scrap