CLASS
VI . SCIENCE
SEPARATION
OF SUBSTANCES
Q.1 Multiple choice questions (Choose the
correct option)
(A) Most of the substances we see around
us are
(a) Pure
Elements (b) Pure
Compounds (c)
Mixtures
(B) A solution of salt in water is a?
(a) Compound
(b)
Homogeneous Mixture (c) Heterogeneous Mixture
(d) Element
(C) The property used in separating a
mixture of two solids by winnowing is
(a) difference in
color
(b)
difference in size
(c) difference in
weight
(d) Attraction by
magnet
(D) Which method is used to obtain pure liquid
from a solution?
(a) Distillation
(b) Condensation
(c) Filtration
(d) Loading
(E) Which of the following can dissolve in
water?
(a) Only Solids
(b) Only solids and liquids
(c) Solids, liquids &
gases
(d) only liquids
Q.2 What is separation?
Q.3 Why the separation of substances is
necessary?
Q.4 What is the basis of separation of
components of mixture?
Q.5 When do we use hand picking as the
method of separation?
Q.6 What is threshing? How is it done?
Q.7 Define winnowing? What is the
principle of using winnowing as method of separation?
Q.8 Where do we find sieving as the method
of separation?
Q.9 You are given a mixture of sand, salt
and iron filling. Suggest some methods for separating all the components of
this mixture?
Q.10 Define filtration? Give 3 examples
where filtration method is used.
Q.11 What is evaporation? Where do we use
this method at home?
Q.12 What method is used to separate salt
from sea water and how?
Q.13 In which cases handpicking is enough
as a method of separation?
Q.14 One method of separation is not
enough. Comment.
Q.15 Differentiate between a pure
substance and a mixture.
Q.16 Is the separation of two immiscible
liquids using separating funnel same as decantation?
Q.17 What do you use to remove discarded
tea leaves from tea?
class- VI
Changes Around Us
FILL IN THE BLANKS
1. The changes that can be reversed are called ______________
changes.
2. The changes that cannot be reversed are called ______________
changes.
3. On heating , the metals _________________
4. On cooling , the metals _________________
5. Burning of incense stick is an ___________________ change.
6 On heating metal rim _______________ and fits into the wooden
wheel.
CHOOSE THE CORRECT ANSWER
1 Ripening of fruit is a ( reversible / irreversible ) change.
2 In ( reversible / irreversible ) change we cannot get back the
original components.
TRUE OR FALSE
1. Growing of trees is an irreversible change. _________
2 Formation of curd from milk is a reversible change .___________
NAME THE FOLLOWING
1 Name any two reversible changes .
2 Name any two irreversible changes.
DISTINGUISH BETWEEN
Reversible and Irreversible changes
CLASSIFY THE FOLLOWING CHANGES INTO REVERSIBLE AND IRREVERSIBLE
CHANGES
1 Crumpling of paper
2 Burning of paper
3 Sawing of wood
4Cooking of food
5 Change of water into water vapour
6 Ironing of clothes
SCIENCE CLASS VI
Unit-15 AIR AROUND US
Q1) Fill in the blanks:
1. The envelope of air that surrounds
the earth is known as __________.
2. Air is a __________of many gases.
3. Burning of a substance can occur
only in the presence of __________.
4. The major component of air is
__________.
5. Plants use __________ for
photosynthesis and __________ for respiration.
6. All living organisms take
in_________and give out_____________during respiration.
7. The burning of fuels produces
__________ gas.
8. __________ contains few gases and fine
dust particles.
9. Animals and plants living in water use
oxygen __________ in water.
10. __________ and __________ present inside
the nose prevent dust particles to enter into the respiratory system.
11. Two processes which maintain balance of
carbon dioxide and oxygen in nature are __________ and __________.
12.Air in motion is called__________.
Q2) Why do mountaineers carry oxygen cylinders with them?
Q3) What is the composition of air.
Q4) The process in which water vapour changes into water droplets
is called condensation. What conditions are required for this process to occur?
Q5) What happens when burning continues in a closed room?
class
-VI
Components Of Food
FILL IN THE BLANKS
1. The main carbohydrates found in our food are in te form of
__________ and ______________.
2. Carbohydrates and fats provide ______________ to our body .
3. Foods containing carbohydrates and fats are also called
______________ giving foods.
4. Foods containing proteins are often called
_________________________ foods.
5. Vitamin ________ gets easily destroyed by heat during cooking.
6. Over eating fat rich food leads to ________________
7. Deficiency diseases can be prevented by taking a
_______________ diet.
8. _____________ help in protecting our body against diseases.
NAME THE FOLLOWING
1. Two sources of carbohydrates . __________________ _____________
2. Two sources of fats __________________ _____________
3. Two sources of protein __________________ ____________
4. Two sources of vitamin C __________________ ____________
5. Disease caused due to deficiency of iron ______________
6. Disease caused due to deficiency of vitamin A _____________
7. Disease caused due to deficiency of iodine_____________
TRUE OR FALSE
1. Dietary fibres are also known as roughage. _________
2. Minerals are needed by our body in large quantity. ___________
3. Our body prepares vitamin D in presence of sunlight. __________
DEFINE THE FOLLOWING
1Nutrients 2 Balanced diet 3 Deficiency diseases
Science Class - VII
MOTION AND TIME
Q1. Define speed. State its S. I. unit.
Q2. Differentiate between uniform and non-uniform motion.
Q3. Describe a simple pendulum. Draw a diagram. What kind of
motion does it show?
Q4. For a simple pendulum; define:-
a) One oscillation
b) Time period
c) Frequency
Q5. A truck travels a distance of 540 km in 4.5 hours. Calculate
its speed.
Q6. The distance between two stations is 1995 km. How much time it
will take to cover this distance at an average speed of 19 km/h?
Q7. A car takes 20 minutes to cover a distance of 15 km. Calculate
its speed in km/h
Chapter 2
Nutrition in Animals
Fill in the blanks:
1. The mode of taking food into the body is called ___________________
2. In the process of ________________ food is broken down in to
simpler substances.
3. The _______________ canal start with mouth and ends in anus.
4. ___________________glands are present in mouth.
5. Saliva helps in the digestion of ___________________ in food.
6. _____________ are the sensory cells present in mouth.
7. The digestive juices of the stomach digest the _____________ in
the food.
8. The ________________released by the bacteria in the mouth
causes tooth decay.
9. Liver secretes ____________ and helps in the digestion of
____________in the food.
10. During the process of digestion, the carbohydrates break down
to _________, the proteins into ______________ and the fats into
______________.
11. Faecal matter is removed from the body by the process of
__________
12. _____________ of amoeba helps to capture food.
13. The patient suffering diarrhea should be treated with
___________.
14. We get hiccups or cough, if by chance food particles enters
the ____
15. Partially digested food in the rumen of herbivores is called
________
16. The process of utilizing absorbed food particles(nutrients)
into the living cells is called ________________.
II) Name the following :
1. 4 types of teeth.
2. Digestive glands in human body.
3. Acid produced in stomach.
4. Scientist who discovered the working of stomach.
5. The sac like structure present between the small intestine
& large intestine in ruminants.
.
Chapter 4
Heat
Fill in the blanks :
1. ______________ is a device used for measuring temperature.
2. The materials which allow heat to pass through them easily are
__________ of heat.
3. Clinical thermometer is used to measure our _____________
4. Wool is poor __________________ of heat and it has air trapped
in between the fibres.
5. In ______________ generally the heat is transferred by
conduction.
6. _______________ metal is used in the bulb of the thermometer.
7. The normal temperature of the human body is __________
True or False :
1. The materials which do not allow heat to pass them easily are
called insulators.
2. In liquids and gases the heat is transferred by conduction.
3. A kink near the bulb of a clinical thermometer prevents mercury
level from falling of its own.
4. We get heat from the sun by radiation.
5. Digital thermometers contain mercury
MATTER AND CHEMICAL
FORMULAE
Write the symbols of the following elements
1) Zinc 6) Phosphorus
2)
Manganese 7) Nickel
3)
Potassium 8) Calcium
4)
Calcium 9) Lead
5) Gold
10) Neon
Write
the formula of the following compounds
1)
Nitric acid 5) Potassium carbonate
2)
Ammonia 6) Calcium dioxide
3)
Sodium hydroxide 7) Carbon monoxide
4)
Hydrogen chloride 8) Sulphuric acid
9)calcium
carbonate. 10) carbondioxide.
Lesson 14
Chemical effects of Electric Current
I Fill in the blanks:
1. Distilled water is
_____________ of electricity.
2. The dissociation of
chemicals into ions due to the passing of electricity through it is the
_____________ of electricity.
3. The distilled water
becomes _____________ of electricity on dissolving salt in it.
4. _____________ are
wires/rods/plates through which electricity enters of leaves an electrolyte.
5. The longer lead of
LED is always connected to the positive terminal of the battery.
6. Name two liquids that
conduct electricity _____________.
7. The passage of
electric current through liquids causes _____________.
8. Coating of
_____________ is deposited on iron to protect it from corrosion.
9. What is LED
10. Define
Electroplating
11. Name some materials
around you which conduct electricity.
12. Name some materials
around you which do not conduct electricity.
POLLUTION OF AIR AND WATER
Q.1 Fill in the blanks:-
(i) By volume about _______ of air is nitrogen and about _________
is oxygen.
(ii) Incomplete burning of fuels produces ________ which is a
_______ gas.
(iii) Carbon monoxide _________ the oxygen carrying capacity of
the blood.
(iv) Petroleum refineries are a major source of gaseous pollutants
like ______ and ______.
(v) _______ used in refrigerators damages the ozone layer of the
atmosphere.
(vi) Ozone layer protects us from the harmful ________ rays of the
sun.
(vii) _______ of the world’s population is without safe drinking
water.
(viii) We can save water by remembering the 3R’s ____, ____ and
________.
(ix) Acid rain is formed by the oxidation followed by dissolution
of ________ and gases in rain water.
Q.2 MULTIPLE CHOISE QUESTIONS: (Choose the most appropriate
answer.?
(A) Which of these causes water pollution?
(a) Sewage (b) Industrial waste (c) Fertilizers and
pesticides (d) All of these
(B) Which of these processes can not remove germs from water?
(a) boiling (b) Filtration through Porous Pot (c) Reverse
Osmosis (d) exposure to UV light
(C) Which of the following is not a pollutant unless present in
excess?
(a) Sulphur Dioxide (b) Carbon dioxide (c) Nitrogen dioxide
(d) carbon monoxide
(D) Which of these can cause acid rain?
(a) Sulphur Dioxide (b) Carbon dioxide (c) Nitrogen (d)
carbon monoxide
Q.3 Define air pollution. What are air pollutants?
Q.4 What are the various sources of air pollutants?
Q.5 What is smog? Why is it harmful?
Q.6 What is acid rain?
Q.7 How is the Taj Mahal affected by air pollution?
Q.8 What is meant by ‘Marble Cancer’?
Q.9 Write the full forms (i) CFC (ii) CNG (iii) LPG (iv) WWF
Q.10 What is greenhouse effect? Name four greenhouse gases.
Q.11 Write a note on global warming mentioning its effects too.
