To present a chemical change quantitatively, an equation must be balanced with the of each type of atom present on both sides. (Two Words)

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.