Question

Rank these five metals — lead, aluminum, gold, copper, and iron — from least dense (in mass per volume) to most dense.

Answer

As you should have guessed, aluminum is the least dense (0.098 pounds per cubic inch). Surprisingly, iron is next (0.284), then copper (0.323), lead at (0.410), and finally gold at (0.698 pounds per cubic inch). (Aluminum is 2713 kilograms per cubic meter, iron is 7861, copper is 8941, lead is 11349, and gold is 19321 kilograms per cubic meter.)