Consider the following sequence of reaction.<br>Na + NH3(g) [X] [Y] [Z] Gas Pure<br>Identify [Z] gas — p Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Tin exists in two main allotropic forms: white tin (tetragonal, metallic, stable above 13.2°C) and grey tin (cubic, non-metallic, stable below 13.2°C). Step 2: At low temperatures, white tin slowly changes into the less dense grey tin, which causes the metal to expand and disintegrate into a powdery grey mass. Step 3: This destructive allotropic transformation is commonly referred to as 'tin plague' or 'tin pest', corresponding to option (b).