Science - Changes around us
Exam Duration: 45 Mins Total Questions : 30
Which of the following are desirable changes?
(i) Drying of clothes
(ii) Growth of weeds
(iii) Cement getting hard when exposed to moisture
(iv) Desalination of sea water
- (a)
Only (i) and (ii)
- (b)
Only (ii) and (iii)
- (c)
Only (i) and (iv)
- (d)
Only (i), (ii) and (iv)
Sheela cooked rice in a rice cooker. What kind of change took place?
(i) irreversible change
(ii) Endothermic change
(iii) Natural change
- (a)
Only (i) and (ii)
- (b)
Only (ii) and (iii)
- (c)
Only (i) and (iii)
- (d)
(i), (ij) and (iii)
Nitrogen reacts with hydrogen under high temperature and pressure and forms ammonia. Which type of change is undergone in the given example?
- (a)
A chemical change
- (b)
A physical change
- (c)
An exothermic reaction
- (d)
A natural change
What is the process by which a substance changes from solid to liquid state called?
- (a)
Boiling
- (b)
Condensation
- (c)
Freezing
- (d)
Melting
On lowering the temperature, a liquid turns into a solid. What is this process called?
- (a)
Condensation
- (b)
Melting
- (c)
Freezing
- (d)
Sublimation
Which of the following does NOT take place during the tearing of a paper?
- (a)
Change of shape
- (b)
Change of size
- (c)
Change of substance
- (d)
All of the above
Which of the following is a natural, nonperiodic change?
- (a)
The heart beat of a human being
- (b)
The low and high tides
- (c)
The eruption of volcanoes
- (d)
The sunrise and sunset
The burning of coal in air is a
- (a)
physical change
- (b)
chemical change
- (c)
reversible change
- (d)
periodic change
What is the process of heating a liquid to a high temperature and rapidly cooling it so that the bacteria is killed called?
- (a)
Pasteurization
- (b)
Chlorination
- (c)
Bacterial disinfection
- (d)
Sublimation
Which of the following is a natural, periodic change?
- (a)
The occurrence of days and nights.
- (b)
The explosion of a bomb.
- (c)
The occurrence of an earthquake.
- (d)
Formation of snow.
Identify the chemical change from the following.
- (a)
The melting of ice
- (b)
The heating of sugar crystals
- (c)
The freezing of water
- (d)
The dissolution of salt in water
What kind of change is the dissolving of sugar in water?
- (a)
Periodic change
- (b)
Reversible change
- (c)
Irreversible change
- (d)
Chemical change
What kind of change is the making of a ring from pure gold?
- (a)
An irreversible, chemical change
- (b)
An irreversible, physical change
- (c)
A reversible, chemical change
- (d)
A reversible, physical change
Based on the flow chart given below, which of the following is correctly represented by P and Q?
- (a)
P Q Boiling Boiling Evaporation - (b)
P Q Evaporation Boiling - (c)
P Q Boiling Condensation - (d)
P Q Evaporation Condensation
The given figure shows the rotation and revolution of the earth on its axis and around the sun respectively.
What kind of change does the earth undergo?
- (a)
Physical change
- (b)
Chemical change
- (c)
Periodic change
- (d)
Undesirable change
Identify the periodic change from the following.
- (a)
The growth of plants
- (b)
The occurrence of storms
- (c)
The occurrence of floods
- (d)
The revolution of the earth
If you pour a few drops of petrol on your palm, you will feel cool as it evaporates. What type of reaction is this?
- (a)
Endothermic reaction
- (b)
Exothermic reaction
- (c)
Chemical reaction
- (d)
Slow reaction
Identify a change that is NOT man-made and is irreversible.
- (a)
The burning of paper
- (b)
The stretching of a spring by a suspended weight
- (c)
Soil erosion due to floods
- (d)
The boiling of an egg
Which of the following changes is slow and periodic?
- (a)
The rotation of the earth
- (b)
The rusting of iron
- (c)
The curdling of milk
- (d)
The evaporation of petrol
Which of the following changes results in the formation of a new substance?
- (a)
Physical
- (b)
Reversible
- (c)
Chemical
- (d)
Periodic
Which of the following is an endothermic reaction?
- (a)
The formation of curd from milk
- (b)
The production of gas when quicklime is added to water
- (c)
The opening of a soda bottle with production of gas
- (d)
The freezing of water
In the given figure, a boy is kicking a football.
What type of change is this?
- (a)
Exothermic
- (b)
Endothermic
- (c)
Physical
- (d)
Chemical
A tray of water was kept in the freezer. The water changed into ice. What kind of change it is?
- (a)
irreversible.
- (b)
chemical change.
- (c)
reversible.
- (d)
no change.
The solute can be______________.
- (a)
solid
- (b)
liquid
- (c)
gas
- (d)
Solid, liquid or gas
Which one of these will dissolve more salt?
- (a)
cold water
- (b)
hot water
- (c)
water at room temperature
- (d)
Water will dissolve same amount of salt at any temperature
Which one of these will dissolve more oxygen easily?
- (a)
cold water
- (b)
hot water
- (c)
warm water
- (d)
all of these
Which one of these is an irreversible change?
- (a)
growth and reproduction
- (b)
curdling of milk
- (c)
formation of cheese from milk
- (d)
all of these
Avika blows air in a balloon. The balloon gets inflated.
What kind of change has occurred in the balloon?
- (a)
reversible change
- (b)
chemical change
- (c)
slow change
- (d)
none of these
Select the right match
Column A | Column B |
i) Heating of mixture of iron and sulphur | A) reversible |
ii) Melting of ice-cream | B) irreversible and chemical change |
iii) Cracking of hot glass in cold water | C) irreversible and physical change |
- (a)
i-C; ii-B; iii-A
- (b)
i-B; ii-A; iii-C
- (c)
i-A; ii-C; iii-B
- (d)
i-B; ii-C; iii-A
Mixing of iron and sulphur is a
- (a)
physical and irreversible change
- (b)
chemical and reversible change
- (c)
chemical and irreversible change
- (d)
reversible change.