Kosuke Morita and his team at RIKEN bombarded bismuth-209 with ions of zinc-70 and detected a chain of six alpha decays stemming from nihonium-278, an isotope of element 113, nihonium-278 decaying to roentgenium-274, roentgenium-274 to meitnerium-270 meitnerium-270 to bohrium-266 bohrium-266 to dubnium-262 dubnium-262 to lawrencium-258 and lawrencium-258 to mendelevium-254. Their success concluded a series of experiments beginning in 2004, during which they synthesized element-113 decaying to dubnium, but the dubnium decayed by spontaneous fission, so did not result in lawrencium or mendelevium with their well-known decay profiles.
Atomic number 113
All six nihonium isotopes are unstable, with the longest having a half life of 20 seconds. Predicted physical and chemical properties can not yet be confirmed.
Radioactivity of the rising sun
Kosuke Morita hoped that the discovery of nihonium in Japan could help the Japanese heal from the Fukushima disaster. In March 2011, a tsunami hit Fukushima and knocked out power at the nuclear power plant, causing the core meltdowns of three reactors and displacing 154,000 people in addition to the 316,000 displaced by the tsunami. Caesium-137 and iodine-131 entered the ocean where strong currents dispersed it, affecting fisheries in the Pacific. Radioactive isotopes contaminated food produced up to 320 kilometers away, which people were urged not to eat. Excessive radioactive iodine-131 was found at 18 water-purification plants, so children were urged not to drink water.