Do all substances have the same chemical formula ? why or why not ?

**40** points asapessay questions (10 points possible) clear image of next, create your own scenario. it can be one of your own real experiences or one you make up. use imagery in your writing to give your instructor a the setting and an action taking pace in your writing explain the structure and functions of the skin at work in your scenario. !

Modern weaponry has increased the number of deaths in wars and violent conflicts.

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.