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

(i) a glass bottle breaking- Physical change

(ii) coal burning in air- Chemical change


(iii) making a cake- Chemical change


(iv) wool being knitted into a sweater- Physical change


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