Chapter 7

What happens when you put a puffed puri into a bowl of water?

Why did the unpuffed puri sink when placed in water?

When a steel plate is gently placed on water, what will it do?

Which of these will float when put into water?

How does the shape of aluminium foil affect its buoyancy?

In the lemon and salt experiment, why does the lemon begin to float after adding salt?

Which method will dissolve sugar most quickly?

After sugar dissolves in water, can you see the sugar crystals?

Which substance can be separated by simple filtration from water?

What phenomenon explains why water left boiling on the stove eventually disappears?

Why can a person float easily in the Dead Sea?

What historical event is used to illustrate the importance of salt in the chapter?

Which of these is a correct way to record your hypothesis before an experiment?

What is the best way to ensure accurate observations in a group experiment?

Identify the noun in the sentence: 'Ayesha gently put the soap in the soap case.'

Identify the verb in the sentence: 'She saw that the case continued to float.'

Which material did Ayesha use to test solubility that did NOT dissolve?

What happens to oil when left in water undisturbed?

Which drop travels fastest when sliding down a tilted surface: oil, water, or sugar solution?

Why did Ayesha's soap case float even with soap in it?

Which factor does NOT affect how quickly sugar dissolves?

What is the purpose of marking [3] and [5] in the student's observation table?

Why might children describe density as 'thick' or 'heavy' instead of scientific terms?

Which of these observations is qualitative rather than quantitative?

What lesson about scientific thinking does Ayesha's soap and puri experiments illustrate?

Which of the following best defines 'evaporation' as per the chapter?

Which process did Gandhi's Dandi March aim to overturn?

Which of these best describes 'mixture' as used in the chapter experiments?

What observation indicates that chalk powder is insoluble in water?

Which experiment question does the poem by Shishir Shobhan Ashthana raise?

How can you separate oil from water after they are mixed?

Which statement best reflects a scientific conclusion from the chapter?

What is condensation?

Which method would you use to separate sand from water?

Simple distillation is best suited for separating:

When heating a mixture of water and alcohol, which vapor escapes first?

Identify the adjective in the sentence: 'The water boiled quickly.'

Why does sugar dissolve faster in hot water compared to cold water?

Which of these is a physical change?

What is chromatography used for?

Why does a paper clip eventually sink if placed gently on water?

Which process is the reverse of evaporation?

Which mixture cannot be separated by evaporation?

Why does hot water expand more than cold water?

Identify the pronoun in the sentence: 'They poured the salt solution carefully.'

What term describes the movement of particles from high to low concentration?

Which factor increases the rate of diffusion?

What is viscosity?

Which has higher viscosity: oil or water?

In paper chromatography, which substance moves fastest up the paper?

Which property allows ice to float on water?

Why does sound travel faster in solids than in liquids?