Use Lewis theory to determine the chemical formula for the compound formed between Mg and Br. Group of answer choices Mg3Br2 Mg2Br3 Mg2Br MgBr2 MgBr

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.