Which one is a chemical change?

1

(a)

Burning of paper

(b)

Germination of seed

(c)

Formation of coal from wood

(d)

All of these

Select a chemical change:

1

(a)

Blooming of a flower

(b)

Stretching of a rubber band

(c)

Burning of petrol

(d)

Condensation of steam

Select a method to prevent rusting:

1

(a)

Sedimentation

(b)

Centrifugation

(c)

Electroplating

(d)

Crystallization

The end product of respiration are

1

(a)

CO₂ and energy

(b)

CO₂ and water

(c)

CO₂ and oxygen

(d)

CO₂ water and energy

Which of the following organism can respire anaerobically?

1

(a)

Amoeba

(b)

Yeast

(c)

Paramecium

(d)

Euglena

Breathing is a process that
(a) provides O₂ to the body
(b) breaks down food to release energy
(c) helps the body to get rid of CO₂
(d) produces water in the cells
Which of the following gives the correct combination of functions of breathing?

1

(a)

(i)and (ii)

(b)

(ii)and (iii)

(c)

(i)and (iii)

(d)

(ii)and (iv)

The colour of blood is red due to the presence of:

1

(a)

Chlorophyll

(b)

Haemoglobin

(c)

Oxygen

(d)

Carbon dioxide

Transport of food in plants takes place through;

1

(a)

Xylem

(b)

Phloem

(c)

Lenticels

(d)

Bark

The excretory substance in fishes is :

1

(a)

Urea

(b)

Ammonia

(c)

Uric acid

(d)

None of these

Which controls blood circulation?

1

(a)

Lungs

(b)

Kidney

(c)

Heart

(d)

Liver

Function of WBCs is/an:

1

(a)

Transport of O₂

(b)

Fight against germ

(c)

Help in clotting of blood

(d)

None of these

Removal of metabolic waste from body is termed as:

1

(a)

Ingestion

(b)

Egestion

(c)

Excretion

(d)

Elimination

The motion of pedal of a bicycle is

1

(a)

Circular

(b)

Periodic

(c)

Straight line

(d)

Oscillatory

Speed is

1

(a)

Distance x time

(b)

Distance / time

(c)

Distance + time

(d)

Distance - time

Distance is a

1

(a)

Vector quantity

(b)

Scalar quantity

(c)

Both (a) and (b)

(d)

None of these

In a graph, on which axis dependent variable is shown ?

1

(a)

x

(b)

y

(c)

On any axis

(d)

Depends on data

One millionth second is

1

(a)

Microsecond

(b)

Nanosecond

(c)

Picosecond

(d)

None of these

A solar day is

1

(a)

24 h

(b)

1440 min

(c)

86400 sec

(d)

All of these

The distance moved by the vehicle is measured by

1

(a)

Odometer

(b)

Galvanometer

(c)

Speedometer

(d)

Thermometer

Following figure shows an oscillating pendulum

Time taken by the bob to move from A to C is 4 and from C to 0 is t₂ The time period of this simple pendulum is :

1

(a)

(t₁ + t₂)

(b)

2(t₁+ t₂)

(c)

3(t₁+ t₂)

(d)

4 (t₁+ t₂)

What colour of flame is observed when magnesium ribbon burnt in air.

2

(a)

How can you say that ripening of a fruit is a chemical change?

2

(a)

Is souring of milk a physical change or a chemical change? Why?

2

(a)

Complete the following reaction Ca (OH₂) + CO₂ \(\longrightarrow\)

2

(a)

What is the nature of magnesium oxide solution?

2

(a)

Name the process by which common salt is obtained from sea water.

2

(a)

Name the metal which is used for galvanising iron.

2

(a)

Name the metals which are mixed (alloyed) with iron to make stainless steel.

2

(a)

Suggest two methods to prevent rusting.

2

(a)

We should eat freshly cut apple. Why?

2

(a)

State the difference between physical and chemical changes.

3

(a)

Ice, water and steam have similar chemical properties. In what respect to these differ?

3

(a)

(a) Why does stainless steel not get rust?
(b) What type of change takes place when sound is produced by radio?
(c) Why do iron pipes coated with zinc do not get rust quickly?

3

(a)

Whether mixing of ash obtained by burning of magnesium with water is a chemical change or physical change ? Give reason in support of your answer. Express the change in the form of equation.

3

(a)

A magnesium strip is burnt. The ash obtained is dissolved in water. What kind of changes are these? Write word equations for these.

3

(a)

Sonu's mother served a glass of hot milk before going to school. As Sonu was in a hurry he forgot to drink the same. Unfortunately, his mother also had gone out. When they came back home, Sonu noticed the changes arose in the milk, which was no more milk, but set into a thick substance known as curd.
Based on this situation answer the following questions:
(i) What is this process of setting milk into curd known as? Is this a physical/chemical change?
(ii) Is this change harmful?
(iii) How does it happen?
(iv) Which value Sonu exhibit her

3

(a)

Can we use the same fuse in a geyser and a television set? Explain.

3

(a)

If cells are placed side by side. Then, how are the terminals of the cells connected?

3

(a)

Explain how a battery can be constructed.

3

(a)

Distinguish between an open circuit and a closed circuit.

3

(a)

1. Boojho made an electromagnet by winding 50 turns of wire over an iron screw. Paheli also made an electromagnet by winding 100 turns over a similar iron screw. Which electromagnet will attract more pins? Give reason.

   4

   (a)

2. Does the electric current have other effect except heating? Name it.

   4

   (a)

1. If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance, called rust.
   (a) Do you think rust is different from iron?
   (b) Can you change rust back into iron by some simple method?
   (c) Do you think the formation of rust on iron is a chemical change?
   (d) Give two other examples of a similar type of change.

   4

   (a)

2. What is rusting? How do we prevent it ?

   4

   (a)

1. In a class, the teacher was explaining a concept from weather and climate chapter. Anand got confused and slowly asked his teacher to repeat again. She smiled and started again. In equatorial belt the climate is hot and wet. It has evergreen rainforest and variety of plants. Similarly the vegetation of tropical region also has variations. The forest located between two tropics is called tropical forest. Desert shows arid region and only xerophytes are observed. These plants show specific modification for their survival in this arid region.
   (a) Which type of forest is formed in equatorial region?
   (b) What are the variation in vegetation seen in tropical forest?
   (c) Give some adaptations of plants that are formed in desert.
   (d) Some places conifers are seen. What are these places?
   (e) What values do we observe in the teacher and Anand?

   4

   (a)

2. Design an activity to show the soil erosion on a barren land.

   4

   (a)

1. Observe the figures carefully and answer the following questions.
   
   (a) Which process is being tested in the activity?
   (b) What is the result of the activity? Give reasons.

   4

   (a)

2. Observe the given figures as A and Band answer the following questions
   
   (a) Among both figures identity which A or B indicates the process of inhalation and which shows the process of exhalation?
   (b) In the figure label the arrows and indicate the direction of
   (i) movement of air (ii) movement of diaphragm (iii) movement of ribs

   4

   (a)

1. Explain the process of reproduction in plants, involving the fusion of cells from male and female parts of a flower.

   4

   (a)

2. Name some fruit bearing plants. Now make a table and describe the method of seed dispersal in these fruits as well as the part which helps in the seed dispersal.

   4

   (a)

1. Observe the given figure and answer the following questions.
   (a) Name the plant?
   (b) Which type of reproduction is seen in this plant?
   (c) Is ginger a root or stem?
   (d) Label the part of this plant?
   

   5

   (a)