It’s elementary, Watson. Things are in flux – from the elements in the air you breathe to party balloons. We investigate the massive, historic loss of nitrogen from the atmosphere and meet the culprits behind a modern-day helium shortage.
But it’s not all a disappearing act: be thankful that oxygen showed up in our atmosphere a few billion years ago. Meanwhile, atom smashers have recently produced some new elements. Their appearance was brief, but long enough to fill out the periodic table.