Start learning →

By volume, about what share of air is oxygen?

A21 per cent
B78 per cent
C50 per cent
D10 per cent
Answer & Solution
Correct answer: A. 21 per cent
1. Nitrogen is about 78 per cent. 2. Oxygen is about 21 per cent. 3. Carbon dioxide and argon are tiny shares. _Source: syllabus Science, Chapter 18, Pollution of Air and Water._
Practise this question with Quill — UPSC CSE →

Keep practising Environment & Ecology

Browse all Environment & Ecology questions for UPSC CSE, or explore more Environment topics.

Start a Environment & Ecology lesson →
Related questions
Wastewater bingoType the numberSort the treatment processesOrganic or inorganic impuritySlice the sewage wordsRun the treatment plantPop the water borne diseasesCatch the treatment steps