State whether the statements given below are True or False.
(i) Stone is transparent, while glass is opaque.
(ii) A notebook has lustre while eraser does not.
(iii) Chalk dissolves in water.
(iv) A piece of wood floats on water. (v) Sugar does not dissolve in water.
(vi) Oil mixes with water.
(vii) Sand settles down in water.
(viii) Vinegar dissolves in water.
(i) False
Stone is not an transparent object because it does not allow light to pass through it. While glass is transparent because it allows light to pass through it.
(ii) False
This statement is false because notebook and eraser both are not metals. So, they both do not contain luster.
(iii) False
Chalk does not dissolve in water because if this get dissolved in water it makes colloidal solution or we can say that it makes an heterogeneous mixture.
(iv) True
Wood floats on water because wood have less density than water.
(v) False
Because sugar dissolves in water and makes a saturated solution.
(vi) False
It is a false statement because oil has less density than water. So oil floats on water but do not mix with water. Oils are non- polar whereas water is polar. But both are immiscible liquids.
(vii) True
This statement is true because when sand mixes in water it makes colloidal solution and when this solution is left undisturbed it settles down in the bottom.
(viii) True
Because vinegar makes a homogeneous mixture or solution when mixes with water.
Draw (a) a leaf, (b) a taproot and (c) a flower, you have studied for Table 7.3.
You are given an iron strip. How will you make it into a magnet?
Name two foods each rich in:
(a) Fats
(b) Starch
(c) Dietary fibre
(d) Protein
A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?
Tick (√) the statements that are correct.
(a) By eating rice alone, we can fulfill nutritional requirement of our body. ( )
(b) Deficiency diseases can be prevented by eating a balanced diet. ( )
(c) Balanced diet for the body should contain a variety of food items. ( )
(d) Meat alone is sufficient to provide all nutrients to the body. ( )
List all items known to you that float on water. Check and see if they will float on an oil or kerosene.
Name the part of the plant which produces its food. Name this process.
Why can a pace or a footstep not be used as a standard unit of length?
Given below are the names of some objects and materials:
Water, basket ball, orange, sugar, globe, apple and earthen pitcher Group them as:
(a) Round shaped and other shapes
(b) Eatables and non eatables
Name two items that are made from coconut fibre.
What is a habitat?
Fill up the blanks with the words given:
herbivore, plant, milk, sugarcane, carnivore
(a) Tiger is a ____________________ because it eats only meat.
(b) Deer eats only plant products and so, is called ______________.
(c) Parrot eats only _________________ products.
(d) The ________________ that we drink, which comes from cows, buffaloes and goats is an animal product.
(e) We get sugar from ___________________.
List five activities that are possible due to the presence of air.
You accidentally dropped your favourite toy and broke it. This is a change you did not want. Can this change be reversed?
Using the "conduction tester" on an object it was found that the bulb begins to glow. Is that object a conductor or an insulator? Explain.
How is a compass used to find directions?
Match the objects given below with the materials from which they could be made. Remember, an object could be made from more than one material and a
given material could be used for making many objects.
Objects Materials
Book Glass
Tumbler Wood
Chair Paper
Toy Leather
Shoes Plastics
A bag of cement lying in the open gets wet due to rain during the night. The next day the sun shines brightly. Do you think the changes, which have occurred in the cement, could be reversed?
Why can a pace or a footstep not be used as a standard unit of length?
Classify the following fibres as natural or synthetic:
nylon, wool, cotton, silk, polyester, jute