This lesson focuses on the copper–tin transitional alloy, a material that bridges the properties of pure copper and bronze. Using a historical coin from the Kingdom of Two Sicilies (1849), students will explore how small variations in alloy composition influence hardness, malleability, and suitability for coinage.
Objectives
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Identify the characteristics of copper–tin transitional alloys.
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Distinguish between pure copper, transitional alloys, and standard bronze.
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Interpret XRF spectra showing variations in tin concentration.
Materials
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Example coin: Dieci Tornesi, Kingdom of Two Sicilies (1849)
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Comparative coin: Polish 5 Groszy (1948)
Lesson Plan
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Introduce the concept of copper-based alloys and their historical applications.
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Examine the composition of the copper–tin transitional alloy (approximately 1% tin) and its advantages over pure copper.
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Compare the transitional alloy to standard bronze (around 4% tin) using XRF spectra.
