Half-Lives of Isotopes Trivia Quiz

Hydrogen (atomic number 1) is the most abundant element in the universe. Despite this, one of its isotopes, Hydrogen-5, has one of (if not the) shortest half-life of any known elemental isotope. Scientists have documented that hydrogen-5 has an infinitesimal half life of 86 yoctoseconds or 8.6 x 10^-23 seconds.

Hydrogen-5 has only been produced in a laboratory by bombarding atoms of hydrogen-3 (aka tritium) with neutrons in the hope that two of them would stick. Surprisingly, atoms of hydrogen-4, 6 and 7 have also been created using this method and were all recorded to last few yoctoseconds longer than hydrogen-5.

Oganesson (atomic number 118) is one of four super-heavy elements to be given a name in 2016 along with nihonium, moscovium and tennessine. Before this, oganesson was referred to as ununoctium.

Oganesson was discovered by the Joint Institute for Nuclear Research (JINR) located in Dubna, Russia who were able to produce the element by bombarding atoms of californium-249 with atoms of calcium-48, which produced oganesson-294, which had a recorded half-life of 0.89 milliseconds. The element was named after Yuri Oganessian, one of the directors of JINR.

Francium (atomic number 87) was discovered by Marguerite Perey in 1939 after observing the decay of the isotope actinium-227. Prior to its discovery, the element was given the placeholder name eka-cesium as an element was previously speculated to exist below cesium (atomic number 55) in the Periodic Table. Marguerite Perey named the element after France, her home country.

Francium has a wide range of known isotopes from francium-197 to francium-233, with half-lives ranging from a few nanoseconds to a few minutes. Its most stable isotope is francium-223, which has a recorded half-life of 22 minutes.

A person may not normally associate the alkali metal sodium (atomic number 11) with radioactivity. Nearly all of the natural sodium in the universe is the stable isotope sodium-23. However, there are several radioactive isotopes of sodium, most notably sodium-24, which can be potentially dangerous if not handled correctly.

Sodium-24 is normally formed when the stable sodium-23 absorbs a stray neutron, such as within some nuclear reactors that use liquid sodium in their cooling systems. It can also be weaponized by using sodium in the construction of a nuclear bomb casing, creating what referred to as a salted bomb, which increases its contamination potential. Sodium-24 has a recorded half-life just short of fifteen hours.

Radon (atomic number 86) is one of the noble gases in Group 18 of the Periodic Table. It is also highly radioactive, emitting alpha particles as it decays. It was first discovered in 1899 by Ernest Rutherford and Robert B. Owens. The most common isotope of the element is radon-222, which has a documented half-life of 3.8 days.

Radon is formed by the natural radioactive decay chains of thorium and uranium and therefore becomes common in places with large uranium deposits. Because of radon's ability to be absorbed by soil and water, radon detectors have been manufactured to be placed in homes to detect the presence of the dangerous element in order to reduce the risk of someone contracting lung cancer due to exposure to the gas.

Polonium (atomic number 84) was discovered by Pierre and Marie Curie in July 1898. The element was named after Poland, where Marie Curie (nee Sklodowska) was born. The most common isotope of the element is polonium-210 which undergoes alpha decay and has a documented half-life of 138 days.

Pierre and Marie Curie's experiments, which allowed them to discover polonium as well as radium later that year, came during a time when the dangers of working with radioactive elements were not yet understood. Pierre Curie died in an accident, but Marie Curie passed away from aplastic anemia which was caused by exposure to radiation during her experiments.

Carbon (atomic number 6) is an element that is essential for organic chemistry. Approximately 99 percent of natural carbon is found as the stable isotope carbon-12. Carbon-14 is most often formed in the Earth's atmosphere when gamma rays convert neutrons within atoms of nitrogen (specifically the isotope nitrogen-14) into protons. Carbon-14 undergoes beta decay, however it is not considered to be dangerous to human and animal health.

Although the element carbon has been known since prehistory, the isotope carbon-14 was only discovered in 1940. Carbon-14 has a documented half-life of approximately 5,730 years. Because of this, carbon-14 has been used by archaeologists to help determine the age of carbon-based items such as bones, cloth and paper up to around 50,000 years.

Technetium (atomic number 43) was the first element to be synthetically produced in a laboratory. It was first discovered in 1937 by Italian scientists Carlo Perrier and Emilio Segre. Prior to this, it was suggested that there had to be an element with atomic number 43 as its properties were predicted by Dmitri Mendeleev, the founder of the Periodic Table. Technetium is the lowest number element to not have any known stable isotopes.

Later in 1962, it was discovered that technetium did exist naturally on Earth but in very trace amounts. The naturally occurring isotope of technetium was found to be technetium-99, which has a half-life of around 211,000 years. There is also a meta-stable isomer, (an isotope in which the nucleons are in an excited state), of the element known as technetium-99m which only has a half-life of approximately 6 hours.

Uranium (atomic number 93) is one of the best known radioactive elements of the Periodic Table. It is one of the elements used in nuclear fission reactors. The element was discovered by German chemist Martin Klaproth in 1789, eight years after the discovery of the planet Uranus, which the element was named after.

The isotope of uranium that is most often used in nuclear reactors is uranium-235 which makes up less than 1 percent of uranium in the universe. Uranium-235 has a documented half-life of approximately 700 million years. Uranium-238, the most common isotope, which is not fissile, has an even longer half-life at almost 4.5 billion years, nearly as long as the age of the Solar System.

Tellurium (atomic number 52) is a metalloid element found in Group 16 of the Periodic Table. It was discovered by Austrian born mineralogist Franz-Joseph Müller von Reichenstein who discovered the element at a mine located in the Transylvania region of what is now Romania.

Although there are stable isotopes of tellurium, its two most abundant isotopes (tellurium-130 and 128) are both considered to be radioactive as they both undergo double beta decay. Tellurium-128 has one of the longest documented half-lives of any elemental isotope (2.2 septillion or 2.2 x 10^24 years) which is longer than the estimated age of the entire universe. Tellurium-130 also has a long half life which is in the quintillion year range.