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Question 3 (e)

Which of the following statement is “true”?
Water vapour condenses to form tiny droplets of water in the upper layers of air where it is cooler.

Question 12.3

Make sentences using the given set of words.

Air, wind, motion, called

Which among the following is a mixture?

The following figure shows chemical change because,

If a mixture of kerosene and water is left undisturbed for a while, which liquid comes to the bottom and which will be at the top?

Fuel + Oxygen (from air) $\to$ Carbon dioxide + Water vapour + Heat.
This reaction shows ___ .

How do we classify materials based on the amount of light they let through them? [3 MARKS]

In the waste treatment plant (WWTP) air is pumped into water to:

Identify the energy "X" given to the beaker at each stage of phase change from the below image.

Formation of clouds is a physical change. Justify. [2 MARKS]

Is rusting of iron a reversible change?

What are the types of natural fibres? Explain. Classify the following based on the different types of natural fibres: [3 MARKS]

What kind of substances are contaminants?

The rotting dead matter in the soil is called _________.

Element A is highly malleable and element B is highly ductile. Raghu wants to cover the surface of his small model of car with one of these elements. Which element should he choose?

Which of the following synthetic fibre is a good absorbent of moisture?

What type of change is making 'Roti' with a dough ball?

The heavier and lighter substances can be separated by using ____

Devices like "takli" are used for:

Animals breathe in air rich in ________ and breathe out air rich in__________.

Name the organ through which an earthworm breathes.

Identify the substances that are made up of vulcanised rubber.

Give two examples where two or more parts of a single plant are used as a food

Question 21

Fill in the blanks to complete the life story of cotton fibre.
My parents, cotton plants were grown in ....... soil and .........climate. The plants bore fruits called...... .I, the cotton fibre was separated from seeds in the cotton bolls by the process of ..... Other cotton fibres and myself were made into yarn by the process of .......... The yarn was ........ to give beautiful colours and then ........ to get cotton fabric.

Sunil accidentally added lemon juice to baking soda and observed the formation of bubbles. What kind of change it is?

Question 2 (b)

State for the following whether it is due to evaporation or condensation:
Steam rising from wet clothes while they are ironed.

Separation of kerosene oil and water is done by ___

Question 16

Earthworms are known as ‘farmer’s friends’. Why?

Explain the process of sepration of mixture of water and soil using filtration technique.

Match the entries in Column - I with those in Column - II
$\begin{array}{cccc}& \text{Column - I}& & \text{Column - II}\\ \text{a.}& \text{A chalk water}& 1& \text{A gaseous}\\ & \text{mixture}& & \text{mixture}\\ \text{b.}& \text{A glucose}& 2& \text{A heterogeneous}\\ & \text{solution}& & \text{solid-liquid mixture}\\ \text{c.}& \text{Carbonated}& 3& \text{A homogeneous}\\ & \text{water}& & \text{solid-liquid mixture}\\ \text{d.}& \text{Air}& 4.& \text{A gas-liquid mixture}\end{array}$

How are synthetic fibers actually made?

Who suggested the idea of having 2 dustbins in the house?

What separation technique is used to separate a mixture of acetone and water?

In November 2016, the national capital city, New Delhi faced a severe increase in air pollution levels which continued for more than 2 weeks. Identify the major contributors to this situation from the options given below.

Which of the following is used for separating small stones from wheat flour?

In preparing tea, the tea leaves are removed from tea by:

Soil with differently sized particles are called

How will you separate a mixture ofchalk powder and water

Under which of the following conditions we can boil water at the room temperature?

John was still not satisfied with the explanation given by Sam regarding organisms that live underwater for most or all of their life. So he asked Sam to demonstrate his explanation physically so that he can have a better understanding. John simply wanted to know about the source of air for the aquatic animals.

Sam decided to use an experiment to explain John so he performed the following experiment.

He took some water in a glass vessel. Heated it slowly on a tripod stand. Well before the water began to boil, he asked John to look carefully at the inner surface of the vessel. John observed that bubbles were coming up.

John asked 'where did these bubbles come from'?

Which of the following can be Sam's answer?

Question 11

Can we reverse the following changes? If yes, suggest the name of the method.
Water into water vapour
Water vapour into water
Ice into water
Curd into milk

Question 5

Name two items that are made from coconut fibre

Explain the processes involved in wool production.