Answer
(a) Meat cooks: Chemical as protein structure is disrupted irreversibly
(b) A candle burns: Physical and chemical. Melting is a physical change, and burning of the wick is a chemical change as it burns to form CO2 and soot.
(c) Wood is attached with nails: Physical change as no chemical reaction occurs
(d) Newspaper yellows with age: Chemical as oxidization makes the paper yellow
Work Step by Step
(a) Meat cooks: Chemical as protein structure is disrupted irreversibly
(b) A candle burns: Physical and chemical. Melting is a physical change, and burning of the wick is a chemical change as it burns to form CO2 and soot.
(c) Wood is attached with nails: Physical change as no chemical reaction occurs
(d) Newspaper yellows with age: Chemical as oxidization makes the paper yellow
