Short answers, pulled from the story.
Lord Rayleigh and Sir William Ramsay discovered argon in 1894. They identified the element while investigating a discrepancy in the density of nitrogen extracted from chemical compounds versus nitrogen drawn from the atmosphere.
Argon has an atomic weight greater than that of potassium, the element immediately following it in the periodic table. This contradiction forced chemists to rethink how elements were organized, leading to the realization that the table is arranged by atomic number rather than atomic weight.
Approximately 700,000 tonnes of argon are produced worldwide every year through the fractional distillation of liquid air in cryogenic air separation units. This process separates liquid nitrogen, argon, and liquid oxygen based on their different boiling points.
Argon is used as an inert shielding gas in welding, for growing silicon and germanium crystals, and in neutrino experiments and dark matter searches. It also preserves national documents stored in argon-filled cases and extends the shelf life of food products.
Argon is considered a dangerous asphyxiant because it is 38% more dense than air and displaces oxygen in closed areas. A 1994 incident in Alaska highlighted the risks of argon tank leakage in confined spaces where the gas is colorless, odorless, and tasteless.
Researchers at the University of Helsinki formed argon fluorohydride in August 2000 by shining ultraviolet light onto frozen argon containing hydrogen fluoride. This compound is stable up to 17 Kelvin or minus 256 degrees Celsius.