alleryWhich gas forms about 21 percent of dry air?
ANitrogen
BArgon
COxygen
DNeon
Answer & Solution
Correct answer: C. Oxygen
1. Dry air has nitrogen, oxygen, argon and small trace gases.
2. Oxygen is about 20.95 percent of dry air.
3. Nitrogen is far higher at about 78 percent, and argon is under 1 percent.
_Source: Wikipedia, Atmosphere of Earth, Lead section_
Keep practising Atmosphere of Earth
Browse all Atmosphere of Earth questions for CTET, or explore more Social Studies topics.
Related questions
Which layer of air holds nearly all atmospheric water vapour?At sea level, sound travels through air at roughly how many metres each second?Which atmospheric region is ionised by solar radiation and affects radio waves?The atmosphere reduces the temperature gap between which two?Ozone depletion is caused chiefly by which pollutants?During the Carboniferous period, oxygen reached a peak of about what share?Which organisms caused the Great Oxygenation Event through photosynthesis?About when did free oxygen begin to appear in Earth's atmosphere?