Which metal is soft, dense, malleable and tarnishes, and is used in batteries, x-ray shielding, weights, and roofing?

• A. Lead
• B. Titanium
• C. Copper
• D. Zinc

Answer: (A)

Soft, dense metals that are easily worked and form a tarnish when exposed to air point to lead. Lead is famously malleable and very dense, and it develops a dull oxide layer over time. This combination makes it ideal for the listed applications: in batteries, the lead-based chemistry is central to lead-acid cells; in X-ray shielding, the metal’s high density blocks X-rays effectively; in weights, its heaviness provides compact masses; and in roofing, lead sheets and flashing are prized for their malleability and weather resistance. Other metals don’t fit as well—titanium is light and very strong; copper is dense and ductile but isn’t used for shielding or roofing to the same extent; zinc is less dense and used mainly for galvanizing.