SEVEN SQUARE ACADEMY
Academic Year – 2016-2017
Primary Section
STD- IV
SUBJECT- SCIENCE
TOPIC- AIR, WATER AND WEATHER
I. Answer the following questions:1. Define weather.
Answer- Weather is the condition of air at a particular time and place.
2. What is humidity?
Answer- The amount of water vapour present in the air is called
humidity.
3. What is atmosphere?
Answer- The blanket of air surrounding the Earth’s surface is known
as atmosphere.
4. What is decantation?
Answer- The process by which water is gently poured out after
sedimentation is called decantation.
5. What do you understand by chlorination ?
Answer- The process by which chlorine is added to kill germs in dirty
water is called chlorination.
6. What is wind?
Answer- Moving air is called wind.
7. Differentiate between revolution and rotation.
AnswerRevolution
i.
The Earth moves around
i.
the sun in its orbit. This
movement is called
revolution.
ii.
Revolution causes changes
iii.
in seasons.
Rotation
The Earth moves on its
own axis. This is called
rotation.
Rotation causes day and
night.
II. Draw water cycle.