Oxygen

Oxygen is the reactive gas we breathe, about 21% of the air. It is also the most common element in Earth's crust by weight, bound up in rocks as oxides and silicates, and it makes up most of the mass of water. Industry separates pure oxygen from liquefied air.

Because it bonds with almost everything, oxygen is part of a huge share of the television's materials. It forms the glassy framework of silicon dioxide and hard oxides such as aluminum oxide, titanium dioxide and indium oxide. It gives acids like acetic acid and terephthalic acid their reactive groups. And blown through molten iron, it burns off the extra carbon to make steel.