This is the deadliest element we sell. Thallium is far more dangerous than mercury or even white phosphorus. Locked inside this ampule this lead-like metal seems harmless enough but we highly highly recommend you resist the urge to break it open to play with the contents. This is because thallium, unlike most other chemicals, can penetrate unbroken skin, poisoning you invisibly. Respect it and keep it between you and the glass and all will be ok!

There aren't many uses for this metal in large part due to its toxicity but one curious application is in very low temperature thermometers. When alloyed with mercury the metal will remain liquid as cold as 60°C below zero!

Note additional options for this element on the Ampules section

CAS 7440-28-0