• Agent Orange
• artificial rain
• acetaldehyde
• acetylene
• acid strength
• Alpha-Pinene
• Alfred Nobel
• Antoine Lavoisier
• aspxhalt
• acetic acid
• acetone
• ammonia
• Activation energy (Ea)
• amide
• acid rain
• Acid dissociation constant (Ka)
• actinide
• Atomic mass unit (amu)
• accelerator
• atomic number