When two substances react to form a new material with different properties, a has occurred.

Stage in which a typical star has completely stopped fusion

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 human activity increases beach erosion?