Fill up the blanks in the following:
(a) The process of changing of water into its vapour is called _________________.
(b) The process of changing water vapour into water is called _________________.
(c) No rainfall for a year or more may lead to _________________ in that region.
(d) Excessive rains may cause _________________.
(a) Evaporation
It is the process of conversion of water into the vapours.
(b) Condensation
The cooling of water vapours and then conversion into water is known as condensation.
(c) Drought
Drought is the condition where lack of water occurs in the excessive amount.
(d) Flood
Flood is the condition in which excess amount of water occurs.
How are clouds formed?
Take out a cooled bottle of water from refrigerator and keep it on a table. After some time you notice a puddle of water around it. Why?
To clean their spectacles, people often breathe out on glasses to make them wet. Explain why the glasses become wet.
State for each of the following whether it is due to evaporation or condensation:
(a) Water drops appear on the outer surface of a glass containing cold water.
(b) Steam rising from wet clothes while they are ironed.
(c) Fog appearing on a cold winter morning.
(d) Blackboard dries up after wiping it.
(e) Steam rising from a hot girdle when water is sprinkled on it.
Which of the following statements are “true” ?
(a) Water vapour is present in air only during the monsoon. ( )
(b) Water evaporates into air from oceans, rivers and lakes but not from the soil.( )
(c) The process of water changing into its vapour, is called evaporation.( )
(d) The evaporation of water takes place only in sunlight.( )
(e) Water vapour condenses to form tiny droplets of water in the upper layers of air where it is cooler.( )
When does a drought occur?
Suppose you want to dry your school uniform quickly. Would spreading it near an anghiti or heater help? If yes, how?
(a) Which kind of garbage is not converted into compost by the redworms?
(b) Have you seen any other organism besides redworms, in your pit? If yes, try to find out their names. Draw pictures of these.
Rearrange the boxes given below to make a sentence that helps us understand opaque objects.
To walk through a waterlogged area, you usually shorten the length of your dress by folding it. Can this change be reversed?
Do you find that all living beings need the same kind of food?
Name the major nutrients in our food.
Classify the following fibres as natural or synthetic:
nylon, wool, cotton, silk, polyester, jute
Name five objects which can be made from wood.
Why do we need to separate different components of a mixture? Give two examples.
Correct the following statements and rewrite them in your notebook.
(a) Stem absorbs water and minerals from the soil.
(b) Leaves hold the plant upright.
(c) Roots conduct water to the leaves.
(d) The number of petals and sepals in a flower is always equal.
(e) If the sepals of a flower are joined together, its petals are also joined together.
(f) If the petals of a flower are joined together, then the pistil is joined to the petal.
Fill in the blanks:
(a) Joints of the bones help in the ——————— of the body.
(b) A combination of bones and cartilages forms the _______ of the body.
(c) The bones at the elbow are joined by a ______________________ joint.
(d) The contraction of the _____________ pulls the bones during movement.
Select those objects from the following which shine:
Glass bowl, plastic toy, steel spoon, cotton shirt
How do plants and animals help each other in the exchange of gases in the atmosphere?
Which of the non-living things listed below, were once part of a living thing?
Butter, Leather, Soil, Wool, Electric bulb, Cooking oil, Salt, Apple, Rubber
What is sieving? Where is it used?
How will you show that air is dissolved in water?
Which of the following leaves have reticulate venation?
Wheat, tulsi, maize, grass, coriander (dhania), China rose
What is the purpose of using an electric switch? Name some electrical gadgets that have switches built into them.
While measuring the length of a knitting needle, the reading of the scale at one end is 3.0 cm and at the other end is 33.1 cm. What is the length of the needle?
Where are poles of a bar magnet located?
In which part of a flower, you are likely to find the ovary?