Related Clues:

• Comfort zone
• Carbon or copper
• Hydrogen or helium
• Chemical building block
• Favorable environment
• Oxygen or aluminum
• Item on a certain table
• Silver or gold
• Factor
• Stomping grounds
• Sodium or chlorine, e.g.
• Palladium, e.g.
• Periodic table listing
• Mercury, e.g.
• Electric device with terminals