FC: Chemistry: Physical & Chemical Changes
1: Physical Change: A reversible change in the physical properties of an object, such as size, shape or smell, without altering the chemical makeup of that object
2: PHYSICAL CHANGE #1 This represents a physical change because the form of gum has changed once it was chewed. Nothing was chemically combined to make this formation, so it is not a chemical change.
3: PHYSICAL CHANGE #2 This represents a physical change because the form changed from a smooth sheet of paper to a crumpled sheet of paper.
4: PHYSICAL CHANGE #3 This also represents a physical change because just the physical form changed, not the chemical content. The can was a regular shape, and then was crushed to form a new shape.
5: PHYSICAL CHANGE #4 This is a physical change because the ice is forming a phase change, from solid to liquid, which just changed the physical form of the ice cube.
7: Chemical Change: an irreversible change where a substance undergoes a chemical reaction and a new substance is formed
8: CHEMICAL CHANGE #1 This represents a chemical change because the egg's content was irreversibly changed. The egg was cooked, chemically changing the egg's substance.
9: CHEMICAL CHANGE #2 Turning bread into toast represents a chemical change because once the bread becomes toast its turns brown and the texture changes and it cannot be turned back into bread.
10: CHEMICAL CHANGE #3 Dissolving salt in water demonstrates a chemical change because the sodium chloride is mixed in the water completely. The only to retrieve the salt is to evaporate the water
11: The End