Page 1 - 3-Lesson Notes-Composition of air, Nitrogen, oxygen and Carbon dioxide

SAI INTERNATIONAL SCHOOL
Class - VI
Subject - Chemistry
Topic – Air Around Us
Sub-Topic – Composition of air - Nitrogen, oxygen and Carbon dioxide

LESSON NOTES

Composition of air

Air is composed of different types of gases. It consists of 78% Nitrogen, 21% Oxygen, the rest
1% of other gases including 0.03% carbon dioxide, water vapour, pollutant particles, and some
inert gases like helium, argon, neon etc. However, their percentage in air varies from place to
place and time to time.

Nitrogen

❖ Nitrogen constitutes 78% (four-fifth) of the air.
❖ It does not support combustion.
❖ Nitrogen is an important constituent of proteins.
❖ Plants and animals need nitrogen to grow. But plants cannot use nitrogen directly
from the air. It has to be converted into the compound form (nitrates and nitrites) and
added to the soil to be absorbed by the plants.
❖ Fertilizers containing nitrogen are also provided to plants. Leguminous plants can
convert atmospheric nitrogen into soluble nitrogenous compounds that can be
absorbed by plants.
❖ Nitrogen is also used to manufacture drugs and dyes.
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