Solution of Chapter 4. Sorting Materials and Groups (NCERT - Science Exemplar Book)

An iron nail is kept in each of the following liquids. In which case would it lose its shine and appear dull?

Pink one material from the following which is completely soluble in water.

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 ?

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.

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?

Which pair of substance among the following would float in a tumbler half filled with water?

Which among the following are commonly used for making a safety pin?

Which of the following materials is not lustrous?

Which of the following statements is not true?

Find the odd out from the following

Which type of the following materials is used for making the front glass (wind screen) of a car?

It was paheli birthday. Her Grandmother gave her two gifts made of metals, One old dull silver spoon and a pair of lustrous gold earring. She was surprised to see difference in the appearance of the two metals. Can you explain the reason for this difference?

Mixtures of red chili powder in water, butter in water, petrol in water, and honey in water were given to Radha, Sudha, Softa, and Raveena, respectively. Whose mixture is in solution form?

On a bright sunny day, Shikha was playing hide and seek with her brother. She hid herself behind a glass door. Do you think her brother will be able to locate her? If yes, Why? If no. why not?

Take a small cotton ball and place it in a tumbler/ bowl filled with water. Observed it for at least 10 minutes. Will it float or sink in water and why?

Which among the following materials would you identify as soft materials and why?

Ice, Rubber band, leaf, eraser, pencil, pearl, a piece of wooden board, cooked rice, pulses and fresh chapatti.

You are provided with the following materials- turmeric, honey, mustard oil, water, glucose, rice flour, groundnut oil.

Make any three pairs of substance where one substance is soluble in the other and any three pairs of substances where one substance remains insoluble in the other substances.

During summer holidays, a group of children collected a lump of salt, green grass, broken glass piece, a small thermal box pen, iron nail, glass marbles, hair, naphthalene ball, a piece of sugar candy(mishri) and tried to group them on the basis of properties given in Table 4.1 below. Help them in filling the Table.

Arrange the jumbled words to arrive at the appropriate names of materials and also write two uses of each.

(a) milaunim

(b) tcaslpi

(c) soekrnee

(d) gavnier

Match the object given in Column I with the materials given in Column II

Pick five objects from the word box given as Fig. 4.1 which are opaque and would sink in water.

chalk, iron, Wood, aluminium, candle, cotton usually look different from each other. Give some properties by which we can prove that materials are different.

Why do you think oxygen dissolved in water is important for the survival of aquatic animals and plants?

Differentiate among opaque, translucent and transparent materials, giving one example of each.

Sugar, salt, mustard oil, sand, sawdust, honey, chalk powder, petals of flower, soil, copper sulphate crystals, glucose, wheat flour are some substances given to paheli. She wants to know whether these substances are soluble in water or not. Help her in identifying soluble and insoluble substances in water.