Lithium is a element represented by the chemical symbol Li and the atomic number 3. It is highly reactive, which means that it is never found naturally in its free form. However, it is found in many compounds and is the 25th most abundant element in the crust of the Earth. It is also found in trace amounts in many organisms, including humans, and it is considered to be an essential trace element. There are two stable isotopes of lithium and all naturally occurring lithium is composed of these isotopes. Let’s find out how many isotopes of lithium have been identified.
How many isotopes does lithium have?
The two stable isotopes of lithium are lithium-7 (7Li) and lithium-6 (6Li). The most common of these is 7Li, which makes up about 92.5% of all lithium atoms and the remaining 7.5% is made up of 6Li. Throughout modern history, 6Li has been highly sought after because it is used to create tritium (hydrogen-3). It has also been used an absorber of neutrons in nuclear fusion reactions. Large amounts of 6Li have been used in hydrogen bombs.
There are also 6 unstable (radioactive) isotopes of lithium that have been identified. These are lithium-4 and lithium-5, along with lithium-8 through to lithium-12. The most stable of these isotopes is 8Li, which has a half-life of just 838 ms. 9Li and 11Li are the only other isotopes with a half-life of more than a millisecond. In fact, the remaining unstable isotopes all have a half life of less than 10 nanoseconds! The most unstable isotope is lithium-4, which decays to helium-3.