A metallurgist investigates the physical properties of two alloys derived from pure iron, \(\text{Fe}\) (atomic radius \(126\text{ pm}\), molar mass \(55.85\text{ g/mol}\)):

- Alloy 1 is formed by introducing carbon, \(\text{C}\) (atomic radius \(77\text{ pm}\), molar mass \(12.01\text{ g/mol}\)), which occupies interstitial sites within the \(\text{Fe}\) crystal lattice with negligible change in unit cell volume.
- Alloy 2 is formed by substituting \(10\%\) of the lattice sites in pure \(\text{Fe}\) with chromium atoms, \(\text{Cr}\) (atomic radius \(128\text{ pm}\), molar mass \(52.00\text{ g/mol}\)).

Which of the following correctly predicts the densities of Alloy 1 and Alloy 2 relative to pure \(\text{Fe}\), and provides the correct particulate justification for the malleability of Alloy 1 compared to pure \(\text{Fe}\)?