What will occur if two reactant molecules collide but do not have the right alignment A. They will react to form a new substances that is not the product
B. They will react to form the product
C. They will not react
D. They will break into smaller particles

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.