Physical and Chemical Changes

Front

A change in which a substance undergoes changes in its physical properties is called _____.

Back

physical change

Front

Browning of an apple after it is cut is an example of ____.

Back

chemical change

Front

When Magnesium ribbon is burnt in oxygen, the product obtained is ___.

Back

Magnesium oxide

Front

When Magnesium ribbon is ignited using a candle flame, it burns with a __________.

Back

brilliant white light

Front

Which of the following is a physical change?

• Rusting of iron
• Melting of wax
• Burning of coal
• Curdling of milk

Back

Melting of wax

Front

Which of the following is a chemical change?

Twinkling of stars

,

Cutting of fruits

,

Cooking of vegetables

,

Boling of water

Back

Cooking of vegetables

Front

A chemical change may involve:
- change in color only
- change in temperature only
- evolution of gas only
- all of the above

Back

all of the above

Front

Which of the following is/are true when milk changes to curd? (i) Its state is changed from liquid to semi solid (ii) It changes color (iii) It changes taste (iv) The change cannot be reversed. Choose the correct option: (i) and (ii) are correct, (ii) and (iii) are correct, (i), (iii) and (iv) are correct, All are correct.

Back

(i), (iii) and (iv) are correct

Front

Which of the following is incorrect for a chemical reaction?

• Heat may be given out but never absorbed
• Sound may be produced
• A color change may take place
• A gas may be evolved

Back

Heat may be given out but never absorbed

Front

Which of the following is false?

• When a candle burns, both physical and chemical changes take place.
• Stretching of a rubber band is not a physical change
• Melting of ice is a physical change
• Dissolving common salt in water is not a chemical change

Back

Stretching of a rubber band is not a physical change