Iron is the 26th chemical element on the periodic table where it is represented by the symbol Fe. It is the most common element on Earth and forms much of the planet’s inner and outer core. It is also the 4th most common element in the crust of the Earth. This metal has many important uses and it is also important for the proper functioning of the human body. All of the natural iron found on Earth is made up of 4 stable isotopes. However, many other isotopes of iron have been identified.
How many isotopes does iron have?
The four stable isotopes of iron are iron-54, iron-56. iron-57 and iron-58. However, iron-54 is considered to be observationally stable which means that it is possibly radioactive (unstable), but has a half life that is older that the age of the planet. The majority of iron found on Earth is iron-56, which makes up about 91.7% of all the naturally occurring iron. Of the other naturally occurring iron, iron-54 makes up 5.8%, iron-57 2.1% and iron-58 0.2%.
There are also 24 known radioactive (unstable) isotopes of iron. Most of these have half lives of less than a minute. However, the longest lived unstable isotope of iron (apart from iron-54) is Iron-60, which has a half life of 2.6 million years.