URANIUM - 92

Widely known for its use in the first atomic bomb, Uranium is a radioactive material whose other uses range from kitchenware to tank-shells. Before the detonation over Hiroshima that shook the globe, Uranium's unique properties had been noticed and pondered by many scientists and entrepreneurs.

Scientists Frederick Soddy and Ernest Rutherford were the first to discover that Uranium had the rare ability to shed protons and neutrons from its nucleus in the form of radioactive decay. During decay, a tiny amount of mass is shed in the form of energy and, true to speculation, this obeyed Einstein's famous equation: E=mc^2. This meant that a tiny amount of mass could be converted into a vast amount of energy, resulting in the atomic bomb.

PROTACTINIUM- 91

Uranium's first Daughter has just one neutron less than Uranium (hence 91) and while dangerously radoiactive is still a naturally occurring element. With a 32,788 year half-life, Protactinium has surprisingly few uses in the modern world and is very difficult to find (the background pictures a lump of mostly Uranium but likely has Protactinium atoms scattered throughout).

THORIUM - 90

Granddaughter of Uranium, Thorium initially excited scientists with hopes of using its radioactivity to produce nuclear energy in power plants due to it's abundance (3 times as much as tin). This idea never reached fruition but during research, tons of the material was mined and stockpiled. in the early 1900's, thorium was a cheap way for 'medicine' companies to incorporate radiation into their remedies, a practice that stopped after multiple high profile deaths. Today Thorium is used for it's cost effectiveness in gas lamps and welding rods as it burns brightly when heat is applied.

RADIUM - 88

Third down from Uranium is Radium. An early 1900's fad element, hundreds of brands and products advertised containing radium for it's newness, marvelous 'medicinal' properties and it's ability to glow. Perhaps most infamously was its use to make glowing watch hands and numbers. The dials were hand painted by workers told to wet the brushes in their mouths for a finer tip. Unbeknownst to them, but fully understood by their employers, this would cause serious health issues. The resulting deaths and losses of livelihood by the famous 'Radium Girls' sped workers' rights movements especially in unsafe work environments.

RADON - 86

The next main element in the decay chain is the short lived radioactive gas, Radon. Despite a half life of just 3.2 days, the gas is abundant as it forms through decaying Uranium and Thorium which is found often in granite bedrock (pictured). As such, granite buildings such as New York's Grand Central Station emit significant amounts of radiation. The fact that Radon seeps from bedrock is of concern to many as it pools in basements and underground parking facilities, giving rise to the expensive industry of channeling Radon out or at least measuring it under buildings.

POLONIUM - 84

Used today in antistatic brushes to attract charges away from film negatives, Polonium was discovered by Pierre and Marie Curie and named for her native Poland. Polonium, thankfully, cannot exist in the open which is lucky because as little as ten nanogams is generally fatal and a coin sized lump would be lethal to anyone in the same room.

LEAD - 82

The final daughter of Uranium is the non-radioactive, but still lethal in many ways (poison, use in bullets etc.), lead which does not decay any further. Lead has been used for thousands of years (often found in pipes), for it's relatively low melting point, the ease with which it can be worked and for protection against radiation.

The journey taken from notorious Uranium to humble Lead is both extraordinary and widely unknown to most people while telling the story of Radiation through the past one and a half centuries.