alleryStart learning →Out of every 100 parts of dry air, about how many parts are oxygen?
A5
B21
C50
D78
Answer & Solution
Correct answer: B. 21
Oxygen makes up about 21 percent of dry air, which is a little more than one fifth.
Keep practising Our Environment
Browse all Our Environment questions for Olympiad (Class 4), or explore more Science topics.
Related questions
What is the dirty water from toilets and drains called?Which chemicals used on farms kill insects and can end up in water?Clouds can be seen because air holds what?What keeps the layer of air around the Earth in place?Which waste can safely go into a compost pit?Raju throws a plastic wrapper into a river. What problem can this cause?Fish in a pond die after a factory pipe starts pouring warm water into it. What is the besWhich one is NOT a natural body of water?