Which metal has the highest tensile strength to density ratio?

Question

What highly flammable metal, easy to ignite when powdered, producing a brilliant white light, and difficult to extinguish, being able to burn in both nitrogen and carbon dioxide, was used in incendiary weapons for firebombing cities in World War II and as a source of illumination in the early days of photography?

Answer 1

Titanium
Titanium is used to produce strong, lightweight alloys for aerospace (jet engines, missiles, and spacecraft), among multiple other applications. Tungsten has the highest tensile strength of any naturally occurring metal, but when density is included in the comparison, titanium has the highest tensile strength to density pound for pound. Chromium is the hardest metal, but not among the hardest in tensile strength.