In the blast furnace, it is so hot that carbon monoxide can be used, in place of carbon, to reduce the iron(III) oxide: iron(III) oxide + carbon monoxide → iron + carbon dioxide The blast ...

Reduction is the gain of electrons by a substance. It is also the loss of oxygen from a substance. For example, copper(II) oxide can be reduced to form copper when it reacts with hydrogen: ...

Oxygen then reacted with the soluble iron to form insoluble iron oxide. Iron oxides fell to the ocean floors as minerals such ...

Oxidized iron is responsible for the colour of rocks on Earth similar to those found on Mars. It is also what makes the blood red. The green tinge is also common in rocks on our planet.