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

• A. Lead
• B. Tin
• C. Aluminium
• D. Titanium

Answer: (A)

Lead has a unique mix of properties that fit this description. It is very soft and malleable, yet dense, which means it can be shaped easily while providing substantial mass. It does tarnish when exposed to air, forming a dull oxide layer. These characteristics, together with its chemical suitability for storing energy in batteries (specifically lead-acid batteries) and its ability to block X-rays due to its high density and atomic number, make it the best fit. Tin is soft but not particularly dense or used for X-ray shielding; aluminium is lightweight and not dense enough for shielding or typical battery use; titanium is strong and light, not the common material for shielding or the described battery type.