1. One quadrillionth 10^(-15)

Encyclopedia: Femto-

• Columbia
• Columbia River
• Columbia tiger lily
• Columbia University
• Columbian
• columbian mammoth
• Columbidae
• columbiform bird
• Columbiformes
• columbine
• columbite
• columbite-tantalite
• columbium
• columbo
• Columbus
• Columbus Day
• columella
• Clinton
• Clinton administration
• Clinton's lily
• clintonia
• Clintonia andrewsiana
• Clintonia borealis
• Clintonia uniflora
• Clio