Physical Changes and Its Characteristics

Q.

Why do fireflies glow at night?

Q.

The by-product of photosynthesis is

1. CO₂

2. H₂0

3. Glucose

4. O₂

Q.

What is sheet erosion?

Q.

How can you prevent ground water depletion?

Q.

How does temperature, light intensity and wind affect transpiration?

Q.

Heating of iodine is a ___________ change.

Q. Increase in the average temperature of Earth's atmosphere is called as ________ .

1. global freezing
2. global warming
3. green house effect
4. global cooling

Q. Forests are also known as the green _______ of the planet.

1. eyes
2. kidney
3. heart
4. lungs

Q.

Write differences between creepers and climbers?

Q. Which amongst the following would be the consequences of forest disappearance?

1. Soil erosion
2. Desertification
3. Rainfall
4. Increase in oxygen level

Q. What is the product of photochemical reaction found in plants?

1. Carbon dioxide, glucose
2. Water, Carbon dioxide
3. Oxygen, water
4. Glucose, oxygen

Q. Grape plant is a type of _____.

1. climber
2. shrub
3. herb
4. creeper

Q.

Give two examples for the following case: Physical changes that are not reversible.

Q. Making of omelette from egg is a/an _____ change.

1. irreversible
2. reversible
3. temporary
4. periodic

Q. Identify the wrongly matched pair.

1. Rusting of iron - Physical change
2. Breaking of glass - Physical change
3. Photosynthesis - Chemical change
4. Folding a paper - Physical change

Q. Clay which is moulded into a caterpillar is an example of

1. Physical change
2. Chemical change
3. Permanent change
4. Irreversible change

Q. Forests help in stabilising the climatic conditions by absorbing ________.

1. carbon dioxide
2. oxygen
3. helium
4. nitrogen

Q.

Classify the following change into physical and chemical changes:

Curdling of milk.

Q. Identify the part of the plant that helps in preventing soil erosion.

1. 
2. 
3. 

Q. Which of the following activities will help in conserving forests?

1. Reusing paper
2. Mining
3. Urbanisation
4. Industrialisation

Q. is the process of cutting down trees for creating agricultural land, pastures, etc.

1. Desertification
2. Deforestation
3. Afforestation

Q.

Hand pumps and deep boring pipes were installed in an area to cater to the water scarcity there. Is this a good practice? Name some alternative measures which ensure enough water supply? [3 MARKS]

Q. Rohit and his classmates after learning about deforestation and its adverse effects, decided to conserve forests. What steps should be taken by them?

1. Replacing already existing green plants with orchards
2. Planting trees in nearby areas
3. Spread awareness about social forestry and its benefits
4. Rehabitation of tribal in their own houses

Q. Clearance of forest for commercial as well as personal use is known as:

1. Sedimentation
2. Deforestation
3. Afforestation
4. Reforestation

Q. Forests helps in maintaining the:

1. fertility of soil
2. rate of evaporation
3. water pollution
4. ecological balance

Q.

Does photorespiration release CO2?

Q. Which of the following is a major consequence of deforestation?

1. Depletion of energy resources
2. Low availability of wooden furniture
3. Global warming
4. Lack of drinking water

Q.

Define physical changes

Q.

Question 17

Place the following statements in a proper order to form a meaningful paragraph.
(a) Which in turn decreases the seepage of rainwater into the ground.
(b) This decreases the open areas like parks and playgrounds.
(c) Increasing population create demand for construction of houses, shops, offices, roads and pavements.
(d) This results in depletion of water table and creates scarcity of more water.

Q. Formation of Fe(II) sulphate solution when Fe nail is dipped in Cu(II) sulphate solution is __.

1. Reversible
2. Cuprous
3. Irreversible
4. Physical