The final state is plasma, in which the atoms of the substance lose the outermost electrons, so that the substance consists of positive ions and negative electrons. In stars, including the sun, all substances — including iron — are in the plasma state.

On Earth, iron is a solid metal. If heated to 2,800 degrees F, it will melt, and at 5,182 degrees F, it will boil. So, to generate gaseous iron, you must heat it to at least this temperature. If further heated, the iron vapor will gradually become plasma, but even at the sun’s surface temperature of 9,941 degrees F, the iron atoms have only lost the outermost of their 26 electrons. In the even hotter corona, where the temperature reaches 27 million degrees, most iron atoms have only lost between six and eight electrons. There are exo- planets that are so hot that they could, in theory, harbor lakes of liquid iron.