Isotopes factsChemistry quiz
How many hydrogen isotopes occur naturally on the Earth?
Three isotopes of hydrogen occur naturally on the Earth: the most frequent protium (1H), deuterium (2H) and tritium (3H). Other isotopes of hydrogen (4H-7H) were created in laboratories and are highly unstable.
What is the name of the most radioactive isotope on the planet?
Polonium 210. 210Po is extremely toxic, with one microgram being enough to kill the average adult (250,000 times more toxic than hydrogen cyanide by weight). 210Po was used to kill Russian dissident and ex-FSB officer Alexander V. Litvinenko in 2006.
Which of the following is not a hydrogen isotope?
Iridium. Protium, deuterium and tritium are hydrogen isotope varieties. Iridium is a chemical element.