Substance iron

It looks like you provided data related to the densities of iron and iron oxide. Here's a summary of the relevant details:

- **Substance**: Iron
- **Density**: 7.9 g/cm³

- **Substance**: Iron Oxide
- **Density**: 1.3 × 10⁻³ g/cm³ (This value appears unusually low for iron oxide; typical densities for iron oxides like FeO or Fe2O3 are much higher, generally ranging from 4 to 5 g/cm³.)

- **Substance**: Another Iron Compound (possibly given as iron oxide again)
- **Density**: 5.2 g/cm³ (This could refer to another specific form of iron oxide.)

If you need further information or specific calculations related to these densities (e.g., comparing mass, volume, or any other properties), please let me know!