Related Clues:

• It's charged
• It's charged in physics
• See 15-Across
• Charged atom
• Elementary particle
• Atomic particle
• Physicist's study
• 'Am ___ time?'
• + or - item
• Cherubini opera
• Negatively charged particle
• It may have an extra electron
• Physics subject
• Greek sorceress
• See 41-Down