If BOD level of water in a reservoir is less than 5 ppm it is highly polluted. — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

Step 1: Identify the layers of Earth's atmosphere based on altitude starting from the surface. Step 2: The layers in order of increasing altitude are: troposphere (0 to ~12 km), stratosphere (~12 to ~50 km), mesosphere (~50 to ~85 km), and thermosphere (~85 to ~500 km). Step 3: This sequence matches option (b).