Chemically, the most common oxidation states of iron are iron (II) and iron (III). Iron shares many properties with other transition metals, including the other group 8 elements, ruthenium and osmium. Iron forms compounds in a wide range of oxidation states, −2 to +7.
Iron (Fe), chemical element and one of the transition elements, the most-used and cheapest metal. Iron makes up 5 percent of Earth’s crust and is second in abundance to aluminum among the metals.
Iron is important for healthy brain development and growth in children, and for the normal production and function of various cells and hormones. Iron from food comes in two forms: heme and non-heme. Heme is found only in animal flesh like meat, poultry, and seafood.
Iron is the main ingredient used to make steel. Raw iron is magnetic (attracted to magnets), and its compound magnetite is permanently magnetic. In some regions iron was used around 1200 BCE. That event is considered the transition from Bronze Age to Iron Age. Iron is a grey, silvery metal.