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.
(a) Condensation
Conversion of water vapours into the water droplets are known as condensation. When the cool water vapours of cold water comes in the contact of environment it becomes hot and convert into the water.
(b) Evaporation
It is because of the water converts into the vapours when hot iron is placed over them.
(c) Condensation
It is because of the conversion of vapours into tiny water droplets.
(d) Evaporation
It is due to evaporation, it mainly happens in high temperature faster.
(e) Evaporation
Due to cooling effect, here evaporation takes place.
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?
When does a drought occur?
To clean their spectacles, people often breathe out on glasses to make them wet. Explain why the glasses become wet.
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.( )
Suppose you want to dry your school uniform quickly. Would spreading it near an anghiti or heater help? If yes, how?
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) 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.
Explain, why speed is important for survival in the grasslands for animals that live there. (Hint: There are few trees or places for animals to hide in grasslands habitats.)
Name two foods each rich in:
(a) Fats
(b) Starch
(c) Dietary fibre
(d) Protein
A drawing sheet changes when you draw a picture on it. Can you reverse this change?
State whether the following statements are true or false:
a) Yarn is made from fibres.
b) Spinning is a process of making fibres.
c) Jute is the outer covering of coconut.
d) The process of removing seed from cotton is called ginning.
e) Weaving of yarn makes a piece of fabric.
f) Silk fibre is obtained from the stem of a plant.
g) Polyester is a natural fibre.
How is a compass used to find directions?
What is the composition of air?
Explain the process of making yarn from fibre.
Which of the things in the following list are nonliving?
Plough, Mushroom, Sewing machine, Radio, Boat, Water hyacinth, Earthworm
How will you separate husk or dirt particles from a given sample of pulses before cooking.
Fill in the blanks:
(i) One metre is ______________ cm.
(ii) Five kilometre is ______________ m.
(iii)Motion of a child on a swing is ______________.
(iv)Motion of the needle of a sewing machine is ______________.
(v) Motion of wheel of a bicycle is______________.