Related Clues:

• Physicist's topic
• Cyclotron 'fodder'
• Physics class subject
• Bohr topic
• Minimal amount of magnesium
• Nuclear power source
• Image used for scene segues on 'The Big Bang Theory'
• A male cat, tiny thing
• Captain ___ (DC Comics superhero)
• A cat that's very small
• Particle depicted on an Emmy
• Place for a proton
• Nothing in cash machine? Not big matter
• Tiny "smashing" target
• Physics building block