Element 26 in our International Year of the Periodic Table series is iron – found in our blood, on the Red Planet, and also responsible for our own planet’s magnetic field.

Blood’s red colour comes from the iron-containing haemoglobin. It’s not just the colour of blood that haemoglobin contributes; it’s also responsible for ferrying oxygen from our lungs to our bodies’ cells. There’s more information on blood chemistry, including why it has a metallic odour, here.

Iron also crops up regularly in our daily lives in the form of rust. Chemically, rust is iron oxide – this is the reason that, technically, we refer to other metals corroding rather than rusting (as they generate different oxides when they react with oxygen in the air). Iron oxide is also the compound behind the appearance of Mars, the Red Planet.

Coming back closer to home, our own planet’s core is 80-85% iron. The temperature and pressure in the outer core is sufficient for the iron there to be molten; the movement of this molten iron is what generates our planet’s magnetic field. The planet’s magnetic field is vital, as it deflects charged particles from the solar wind which would otherwise strip away the planet’s atmosphere.

Remember, you can keep track of all of the previous entries in this series on the site here, or on the Royal Society of Chemistry’s dedicated page.