Identify each of the following observations as evidence of either a physical change or a chemical change. (a) A piece of copper is heated until it...

Identify each of the following observations as evidence of either a physical change or a chemical change. (a) A piece of copper is heated until it melts. (b) A piece of aluminum corrodes in a solution of acid. (c) A piece of paper burns in a candle flame. (d) A piece of plastic is stretched until it breaks. (e) Table salt boils at 1465°C.