Tamilnadu BoardEnglish MediumSTD 8ScienceAir.1 Mark
Question
Write about occurrence of carbon dioxide.
✓
Answer
Carbon dioxide is present in air to the extent of about $0.03 \%$ in volume. It is evolved by the plants and animals during respiration and is produced during fermentation reactions. Much of the naturally occurring $CO _2$ is emitted from the magma through volcanoes. $CO _2$ may also originate from the bio - degradation of oil and gases. Human $CO _2$ emissions upset the natural balance of the carbon cycle.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.