(a) Give the main differences between physical changes and chemical changes.
(b) Which of the following are chemical changes and which physical ? Give reason.
(i) a glass bottle breaking (ii) coal burning in air
(iii) making a cake (iv) wool being knitted into a sweater
(a) Give the main differences between physical changes and chemical changes.
(b) Which of the following are chemical changes and which physical ? Give reason.
(i) a glass bottle breaking (ii) coal burning in air
(iii) making a cake (iv) wool being knitted into a sweater
a)Difference between a physical change and chemical change are as follows-
1 - physical change is reversible but chemical change is irreversible.
2- It is a change where the properties and composition of substance remain same but in chemical change new substance is formed.
3- physical change is temporary whereas the Chemical change is permanent.
(b) Which of the following are chemical changes and which physical? Give reason.
(i) a glass bottle breaking ---->
Physical change because it is a reversible process and does not form a new product.
(ii) coal burning in air ------->
Chemical change because it is an irreversible process and forms a new product, CO2.
(iii) making a cake ------->
Chemical change because it is an irreversible process and forms a new product.
(iv) wool being knitted into a sweater ------>
Physical change because it is a reversible process and does not form a new product.
a)Difference between a physical change and chemical change are as follows-
1 - physical change is reversible but chemical change is irreversible.
2- It is a change where the properties and composition of substance remain same but in chemical change new substance is formed.
3- physical change is temporary whereas the Chemical change is permanent.
(b) Which of the following are chemical changes and which physical? Give reason.
(i) a glass bottle breaking ---->
Physical change because it is a reversible process and does not form a new product.
(ii) coal burning in air ------->
Chemical change because it is an irreversible process and forms a new product, CO2.
(iii) making a cake ------->
Chemical change because it is an irreversible process and forms a new product.
(iv) wool being knitted into a sweater ------>
Physical change because it is a reversible process and does not form a new product.
