What is the state of matter of Mg?

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.

Ahypothesis must be testable and falsifiable to be considered scientific a. trueb. false

How do you determine the percent yield of a chemical reaction