system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: what is Ferromagnetism and why does it mean the iron in your blood is not attracted to an MRI?
gpt
Really simple answer - iron atoms on their own are always magnetic, and that phenomenon is called ferromagnetism. In your body, there's basically no free iron as it's all bound up in other compounds - hemoglobin bound to red blood cells, or a protein called ferritin that binds up any free iron to store it and release it later when needed.