Could someone please help me in which goes which?

Layers of rock containing fossils, like the layers illustrated here, are most likely composed of rocks.

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.

What must occur for air masses to form fronts