- Learning Outcome)
Classifies object, living beings and process based on observed properties.
Take a glass of water, pour the substances given below and stir them properly. After (3)
that observe the glass properly and classify soluble and insoluble substances on the
basis of observation.
1. Sugar(half teaspoon) 2. Mustard seeds(half teaspoon) 3.Two to three drops of coconut
oil
ing items are
Answers
uestion 1.
An iron nail is kept in each of the following liquids. In which case would it lose its shine and appear dull?
(a) Mustard oil
(b) Soft drink
(c) Coconut oil
(d) Kerosene
Solution:
(b) : Soft drinks contain water, carbon dioxide and acid due to which iron nail is corroded and appears dull.
Question 2.
Pick one material from the following which is completely soluble in water.
(a) Chalk powder
(b) Tea leaves
(c) Glucose
(d) Sawdust
Solution:
(c): Glucose is completely soluble in water.
Question 3.
You are provided with the following materials
(i) magnifying glass
(ii) mirror
(iii) stainless steel plate
(iv) glass tumbler.
Which of the above materials will you identify as transparent?
(a) (i) and (ii)
(b) (i) and (iii)
(c) (i) and (iv)
(d) (iii) and (iv)
Solution:
(c): Magnifying glass and glass tumbler are transparent.
Question 4.
Boojho found a bag containing the following materials.
(i) Mirror
(ii) Paper stained with oil
(iii) Magnet
(iv) Glass spectacles
Help Boojho in finding out the material(s) which is/ are opaque.
Solution:
(a) (i) only
(b) (iv) only
(c) (i) and (iii)
(d) (ii) and (iv)
Solution:
(c): Mirror is opaque since it is painted on one side. Magnet is opaque since it is made up of iron metal.
Question 5.
While doing an activity in class, the teacher asked Paheli to .handover a translucent material. Which among the following materials will Paheli pick and give her teacher?
(a) Glass tumbler
(b) Mirror
(c) Muslin cloth
(d) Aluminium foil
Solution:
(c): Glass tumbler is transparent, mirror and aluminum foil are opaque while muslin cloth is translucent since we can see through it though not clearly.
Question 6.
Which pair of substances among the following would float in a tumbler half filled with water?
(a) Cotton thread, thermocol
(b) Feather, plastic ball
(c) Pin, oil drops
(d) Rubber band, coin
Solution:
(b): Feather and plastic ball will float on water because they are lighter than water.
Question 7.
Which among the following are commonly used for making a safety pin?
(a) Wood and glass
(b) Plastic and glass
(c) Leather and plastic
(d) Steel and plastic
Solution:
(d): Steel and plastic are used for making safety pins. Steel can be moulded to get sharp points and plastic is used to seal the edges.
Question 8.
Which of the following materials is not lustrous?
(a) Gold
(b) Silver
(c) Wood
(d) Diamond
Solution:
(c): Wood is not a crystalline substance and has no lusture.
Question 9.
Which of the following statements is not true?
(a) Materials are grouped for convenience.
(b) Materials are grouped to study their properties.
(c) Materials are grouped for fun.
(d) Materials are grouped according to their uses.
Solution:
(c): Materials are not grouped for fun. They are grouped for convenience, to study their properties and according to their uses in systematic manner.
Question 10.
Find the odd one out from the following.
(a) Tawa
(b) Spade
(c) Pressure cooker
(d) Eraser
Solution:
(d) : Tawa, pressure cooker and spade are made up of metal while eraser is made up of rubber.
Question 11.
Which type of the following materials is used for making the front glass (wind screen) of a car?
(a) Transparent
(b) Translucent
(c) Opaque
(d) All the above
Solution:
(a): Transparent glass is used for making the wind screen of a car so that everything can be clearly seen.