The element that removes oxygen from iron oxide (FeO) is carbon (C). This process is called reduction and is the foundation of how we extract iron from its ore.

Here's how it works:

1. Heating: Iron oxide is heated in the presence of carbon (usually in the form of coke).

2. Reaction: Carbon reacts with the oxygen in the iron oxide, forming carbon dioxide (CO2).

3. Iron Formation: This leaves behind pure iron (Fe).

The chemical equation for this reaction is:

2FeO + C → 2Fe + CO2

This is a simplified explanation, but it captures the fundamental process of removing oxygen from iron oxide using carbon.