7Class - Science - Changes around Us Test 3

In dry cleaning shops, they dry clean the clothes by

• water
• soap
• tetra chloro ethylene
• alchohol

This change may be reversed by reversing the experimental conditions

• Chemical
• Physical
• Periodic
• None

Formation of dew is a ___________ change

• Chemical
• Periodic
• Physical
• Fast

Chemical change

• Permanent change
• No new substances are formed
• It is temporary change
• Fase change

An iro nail is dropped in a beaker containing acidified copper sulphate solution. Iron nail gets

• red coating of copper
• blue coating of copper
• green coating of copper
• light green coating of copper

Browning of vegetables can be prevented by soaking them in ______ water

• Lemon juice
• Salt
• Lemon and salt
• Lemon and sugar

When sugar is added to water, it becomes sweet

• It is a chemical change because because new substance is formed
• It is a chemical change because because there is exchange of heat
• It is a chemical change because because there is only change in colour
• It is a physical change because original substances can be recovered

This is a physical change

• Grinding of wheat
• Photosynthesis
• Curding of milk
• Burning of candle

Neutraliation is a

• Physical change
• Chemical change
• Physical or cheical
• Neither physical nor chemical

Boiling of egg is __________ change

• Physical
• Chemical
• Neutralisation
• Physical and Chemical