CBSE Class 7 Science Sample Paper SA-1
Time: 3 hour/ M.M.-80
All questions are compulsory.
1- Select the correct option.(5)
i) The organisms which make their own food are called
ii) The art of growing silkworms for silk is called
iii) Heat from the sun reaches us by the process of
d) All of these
iii) Which is not a base
b) lime water
iv) Which food item contains ascorbic acid
v) Which of these is a chemical change
b) mixing sugar in water
c) mixing salt in water
d) cutting of wood
vi) Combustion takes place in the presence of
a) carbon dioxide
vii) Which animals turns itself into a feathery ball so that it can sleep in holes in the trees
viii) This animal possesses blubber under its skin
a) polar bear
ix) The factor that affects the development of a cyclon is
b) wind speed
c) level of humidity
d) all of these
2- Fill in the blanks.(5)
i) Air around us exert______________________.
ii) The __________is called wind.
iii) Cyclones are called __________in the Philippines.
iv) Distilled water is a _________________solution.
v) Phenolphthalein turns __________in colour in base.
vi) __________is an indicator extracted from lichens.
vii) An ant bite can be treated by applying a __________solution.
viii) On cooling the temperature of an object__________.
ix) Most substances _________on heating and _______on cooling.
x) Radiation is the process of transfer of heat in which a________ is not required.
3- Write true/false. (5)
i) Vinegar is dilute lactic acid.
ii) Chemical name of vitamin D is Ascorbic Acid.
iii) When an acid reacts with a base neutralization occurs.
iv) Acids feel slippery to touch.
v) Acids produce hydrogen ions when dissolved in water.
vi) Tearing of paper is physical change.
vii) The presence of oxygen and water is necessary for rusting of iron.
viii) Copper is more reactive than iron.
ix) A physical change can be reversed.
x) Which a chemical change, no new substance is formed.
4- Give one word for the following.(5)
i) Special substances present in food________________
ii) Finger-like projections present in the small intestine_________
iii) Wool is a plant fibre__________
iv) Woolen fabric dries slower than cotton______________
v) Indians were the first to produce silk_____________
6- Match the following.(6)
i) Decomposition of A magnesium ribbon
ii) Cutting an Old leaves
iii) Blowing of Rubber band
iv) Stretching of a Balloons
v) Souring of Copper wire
vi) Burning of Milk
7- Give reason for the following.(4)
i) Explosion of crackers is a chemical change.
ii) Baking soda fizzes with vinegar.
iii) Gardeners add lime to soil.
iv) You must brush your teeth after eating grapes.
8- Define the following terms.(8)
9- Write short answer. Attempt any eight.(16)
i) What is a tornado?
ii) What is eye of cyclone?
iii) Discuss some adaptation shown by polar bear.
iv) How does a penguin get rid of all the excess salt in its body?
v) What is acid rain?
vi) Why is mercury preferred as a thermometric liquid?
vii) Name the Indian breeds of sheep that yield wool?
viii) What hazards do people working in the wool industry face?
ix) What is Tussar?
x) Differentiate between acid and base.
10- Answer in detail. Attempt any four.(16)
i) Mention three major characteristics of acids. Mention the use of acids in everyday life.
ii) How is carding of wool done?
iii) State the basic characteristics or effects of heat.
iv) What is rusting of iron? Name two factors which cause rusting and suggest two ways to prevent it.
v) Differentiate between chemical and physical change.
vi) Why is the rain forest home to more than half of the animal life on earth?
11- Attempt any two.(10)
i) How does amoeba get its nutrition? Explain with diagram.
ii) Explain with diagram involved in extracting silk from the silk moth.
iii) What is a sea breeze and how is it created? Explain with diagram.