Question

Difference btw physical and chemical changes 5points

Answer 1

$\huge\bf{Answer :}$

Physical change :

• Physical change can be reversed.

• Physical change brings about changes only in the physical properties of the substances.

• Physical change is a temporary change.

• No new substance is formed in a physical change.

• Absorption does not take place during physical change.

• There is no change in the chemical composition of the substance.

${\bigstar}$ Some examples of physical changes are:

1. Melting of butter.
2. Cutting of grass.
3. Dissolving salt in water.
4. Formation of fog.
5. A magnet attracting iron nails.
6. Glowing of an electric bulb.

Chemical change :

• Chemical changes can't be reversed.

• Chemical change brings changes in the chemical properties of the substances.

• A chemical change is a permanent change.

• A new substance is formed in a chemical change.

• Absorption takes place during a chemical change.

• There is always a change in the chemical composition of the substance.

${\bigstar}$ Some examples of chemical changes are:

1. An almirah gets rust
2. Electrolysis of water.
3. Burning of the candle.
4. Digestion of food.
5. Moulding of glass.
6. Photosynthesis in plants.
7. Burning of magnesium ribbon in air.
8. Burning of wood.

Answer 2

Answer:-

The difference between physical and chemical change are:-

Physical change

• Physical change is a temporary change.
• There is a change in physical properties of a substance.
• No new substance are produced.
• This change can be easily reversed.
• There is no change in mass.
• There is no energy change.
• The compostion of the substance doesn't change.

Explanation With An Example:

Ex :- Dissolution of sugar in water.

It is physical change because

↪No new substances are formed.

↪It is temporary change.

↪It can be reversed because we can get back the sugar in an original form.

↪It is not accompanied by energy change.

• Some more examples are:-

▪ Dissolution of sugar in water.

▪ Melting of butter.

▪ Sublimation of iodine

▪ Evaporation of water

▪ Freezing of water, many more.

Chemical change

• It is a permanent change.
• New substances are produced.
• This change is irreversible.
• There is a change in mass of the substance.
• There is a gain or loss of energy.
• The compositions of the substances change.

Explanation With An Example:

Ex:- Cooking of vegetables

↪New substances are formed.

↪It is permanent change.

↪It cannot reversed because we can't get back the vegetables in an original form.

↪ Energy is always absorbed or evolved.

• Some more examples are:-

▪ Rusting of Iron

▪ Ripening of fruit

▪ Burning of paper

▪ Respiration

▪ Burning of coal, many more.

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What are physical properties?

Ans) The properties associated with physical change which can be determined by simple physical observation is called physical properties.

What are chemical properties??

Ans) The properties associated with chemical change which can be determined by chemical reactions is called chemical properties.