CO₂ plays a pivotal role in regulating the planet's temperature. Rounding out the top five is neon, the element that makes your favorite signs glow. Like argon, neon exists in trace amounts ...

Neon stood out and stands out,” UNLV history professor Michael Green said. “Las Vegas stood out and stands out.” ...

Fellmer said the element neon was discovered in the late 19th century and not used with glass tubes until the early 20th century. Neon light debuted in Paris in 1910, and the first neon sign was ...