---
title: "Steel is an interstitial alloy formed by introducing a small percentage of carbon into iron. Pure iron is relatively soft and malleable, whereas steel is noticeably harder and less malleable. Which of the following correctly compares the malleability of the two substances and provides the best particulate-level justification?"
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url: "https://nerd-notes.com/ubq/120012/"
date_modified: "2026-08-21T08:31:52+00:00"
---

# Steel is an interstitial alloy formed by introducing a small percentage of carbon into iron. Pure iron is relatively soft and malleable, whereas steel is noticeably harder and less malleable. Which of the following correctly compares the malleability of the two substances and provides the best particulate-level justification?

Steel is an interstitial alloy formed by introducing a small percentage of carbon into iron. Pure iron is relatively soft and malleable, whereas steel is noticeably harder and less malleable. Which of the following correctly compares the malleability of the two substances and provides the best particulate-level justification?

![A diagram showing two side-by-side square containers labeled Pure Fe on the left and Steel on the right. A legend at the top defines: large open circle = Fe atom, small filled circle = C atom. The left container contains 16 large open circles arranged in a uniform 4 by 4 square grid, with adjacent circles in direct contact. The right container contains the same uniform 4 by 4 square grid of 16 large open circles, with exactly 4 small filled circles placed in the interstitial spaces between the large open circles in the interior of the grid. No other particles, labels, text, or annotations appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787301111-ddp3c8.jpg)

- **A.** Pure \(\text{Fe}\) is less malleable than steel because the uniform size of the \(\text{Fe}\) atoms prevents planes of atoms from sliding past one another.
- **B.** Pure \(\text{Fe}\) is less malleable than steel because delocalized valence electrons create rigid directional bonds that lock \(\text{Fe}\) atoms in fixed positions.
- **C.** Steel is less malleable than pure \(\text{Fe}\) because \(\text{C}\) atoms substitute directly for \(\text{Fe}\) atoms in the lattice, weakening the metallic bonding throughout the crystal.
- **D.** Steel is less malleable than pure \(\text{Fe}\) because the smaller \(\text{C}\) atoms occupy interstitial spaces in the lattice, hindering layers of \(\text{Fe}\) atoms from easily sliding past one another.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/120012/*