In architectural conservation, researchers analyzed medieval stained glass windows to understand their durability. They found that glass containing high concentrations of sodium and calcium is highly susceptible to corrosion when exposed to atmospheric moisture, which reacts with sodium to form a silica-degrading alkaline film. However, glass composed primarily of potassium and lead shows almost no surface degradation under identical environmental conditions. Since potassium-lead glass does not readily react with moisture to form this alkaline film, ______
Which choice most logically completes the text?
- Amedieval artisans deliberately selected potassium and lead to ensure their windows would last for centuries.
- it is less likely to undergo moisture-induced silica degradation than sodium-calcium glass is.Answer
- Cany glass containing potassium and lead will remain entirely free from all forms of chemical weathering.
- Dsodium-calcium glass is more durable than potassium-lead glass when exposed to high levels of humidity.
Answer
it is less likely to undergo moisture-induced silica degradation than sodium-calcium glass is.
The correct option is supported because the passage outlines a direct causal chain for sodium-calcium glass: exposure to moisture leads to a reaction forming an alkaline film, which in turn degrades the silica. Because potassium-lead glass is shown not to undergo this reaction, it logically follows that it is less susceptible to this specific process of silica degradation.
Step-by-Step Solution
Key Concept
Drawing logical inferences from comparative premises