Where in the periodic table would you find elements with the same number of energy levels? a. group o only b. within any group c. within any period d. all the non-metals

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.