Fifty-four — African nations

Africa has 54 recognized states — more than any other continent. Most gained independence during the decolonization of the 1950s–1970s. The African Union unites all 54 countries.

Studio 54 was a New York nightclub opened in 1977 that became a symbol of the disco era. Andy Warhol, Mick Jagger, and Liza Minnelli were regulars. It closed in 1980 but became a pop culture legend.

Xenon (Xe) is a noble gas with atomic number 54. Used in high-intensity xenon lamps (in car headlights and cinema projectors), as well as in nuclear medicine and ion propulsion spacecraft engines.