Answer
(a) Alcohol burns: Chemical change as alcohol reacts with oxygen while burning
(b) Sugar crystallizes: Physical change as the chemical composition remains unchanged and crystal is formed
(c) Gas bubbles rise out of a glass of soda: Physical change as the gas bubble changes its medium from liquid to air
(d) A tomato ripens: Chemical change as breakdown of chemical components happens in the tomato
Work Step by Step
(a) Alcohol burns: Chemical change as alcohol reacts with oxygen while burning
(b) Sugar crystallizes: Physical change as the chemical composition remains unchanged and crystal is formed
(c) Gas bubbles rise out of a glass of soda: Physical change as the gas bubble changes its medium from liquid to air
(d) A tomato ripens: Chemical change as breakdown of chemical components happens in the tomato