Element 88 in our International Year of the Periodic Table series is radium. Radium is highly radioactive, but the dangers of radiation were only fully understood after it had been used for a number of years in consumer products.
Element 87 in our International Year of the Periodic Table series is francium. Vanishingly rare, francium is unstable and radioactive, and also doesn’t conform to expectations about its reactivity.
Element 86 in our International Year of the Periodic Table series is radon. Radon is the biggest source of natural background radiation and also has associated health risks.
Element 85 in our International Year of the Periodic Table series is astatine. Astatine is incredibly scarce on Earth, and there’s so little of it around that we don’t know a great deal about it.
Element 84 in our International Year of the Periodic Table series is polonium. Polonium is a highly radioactive element which has been used as a heat source for space travel and exploration. It was also the centre of attention in a high-profile poisoning several years ago.
Element 83 in our International Year of the Periodic Table series is bismuth. Bismuth’s compounds are used in some cosmetics and are also behind the fizzing, crackling sounds of some fireworks.