An unknown metal has a density of 10.51 g/ml and a mass of 287.8 g. What is the unknown metal's volume?

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.