Related Clues:

• Tin or tungsten
• Neon or nobelium, e.g.
• See 39 Across
• Gold and silver, e.g.
• Weather, with "the"
• Copper and carbon
• Comfort zone
• Carbon or copper
• Hydrogen or helium
• Chemical building block
• Fire, air, water and earth
• Favorable environment
• Oxygen or aluminum
• Item on a certain table
• Silver or gold