---
title: "A particulate representation of an iron-carbon alloy (steel) is shown above. Which of the following correctly classifies the alloy and explains why it is less malleable than pure iron?"
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date_modified: "2026-08-21T06:53:51+00:00"
---

# A particulate representation of an iron-carbon alloy (steel) is shown above. Which of the following correctly classifies the alloy and explains why it is less malleable than pure iron?

A particulate representation of an iron-carbon alloy (steel) is shown above. Which of the following correctly classifies the alloy and explains why it is less malleable than pure iron?

![A cross-section diagram of a metal lattice. A legend at the upper right displays: large open circle = \(\text{Fe}\) atom, small solid black circle = \(\text{C}\) atom. In the main rectangular viewing area, there are exactly 12 large open circles arranged in 3 horizontal rows of 4 circles each, in close contact. In the interstitial voids between the rows of large open circles, there are exactly 4 small solid black circles positioned entirely within the spaces between the large circles. No other particles, labels, text, or annotations appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787295230-nABlO0.jpg)

- **A.** It is a substitutional alloy, because the carbon atoms replace iron atoms in the crystal lattice, preventing electron delocalization.
- **B.** It is an interstitial alloy, because the smaller carbon atoms occupy spaces between the iron atoms, making it more difficult for the layers of atoms to slide past one another.
- **C.** It is an interstitial alloy, because the carbon atoms form rigid directional covalent bonds throughout the lattice, preventing melting.
- **D.** It is a substitutional alloy, because atoms of similar radii substitute into lattice sites, decreasing the density of the metal.

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