Physical and Chemical Properties and Changes
KEY
1. What is the difference between a property and a change?
Properties = characteristics that are observed / Changes = something different being made
Consider a sheet of paper to answer the following questions.
2. What are the physical properties of the paper?
flat, white, rectangular, thin, smooth (texture), translucent, a solid, current mass, density, solubility
3. What are the chemical properties of the paper?
flammable, reacts to water and/or air
Tear the sheet of notebook paper into tiny pieces.
5. Tearing was a ( property / change ).
6. Was this property or change considered physical or chemical? Explain your answer.
all the same characteristics apply, we just have smaller pieces
Light a match and hold it to the paper.
7. What did you observe?
flames, smoke, change in color, new odor, fell apart into ashes
8. This was a ( property / change ).
9. Was this property or change considered physical or chemical? Explain your answer.
we have a new substance and can't change our product back into the original paper
10. What are the indications (clues) of chemical change? (pg 91 in textbook!)
changed color - became black/gray
new odor
saw smoke
emitted light
broke apart into ashes
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Other clues of chemical changes: endothermic/exothermic, bubbling, fizzing, new taste, decomposing,
forming a solid (precipitate)
Describing Matter - Chapter 2, Section 2… FLIPCHART
1. Define physical property. an observable characteristic… can be observed or measured without changing
the identity of the matter
2. What are six examples of physical properties? (there more than 6!)
state of matter, thermal/electrical conductivity, malleability, ductility, solubility, density, color, mass, shape,
size, current odor, volume, texture, current taste, texture, luster
3. Describe some ways that you can separate mixtures by their physical properties.
distillation, centrifuge, sift/filter, sorting, magnetism, evaporation
4. Define chemical property and give an example.
ability to change into something new with different properties… like the ability to catch fire or burn or be
combustible or ability to react to air or react to an acid or ability to corrode
5. Define physical change. a change that affects a physical property but can be undone easily
6. Give 3 examples of a physical change. page 49
cutting, ripping, or breaking something, changing the state like melting butter or freezing water, dissolving
sugar into tea (evaporate tea to get sugar back)
7. Define chemical change. change that makes something different with new properties and it is chemically
different… it cannot be easily undone, even using chemical processes
8. Give 3 examples of a chemical change. page 50
milk souring, food rotting, baking a cake, cooking an egg, silver tarnishing, burning something, car rusting
9. Define the Law of Conservation of Mass.
matter can neither be created or destroyed, but can be changed from one form to another
10. Give an example of the Law of Conservation of Mass and explain why it demonstrates the Law.
burning wood - you would have the same amount of mass, but it would be the ashes and the gases given off
(hard to capture) or milk souring - you'd still have the same amount in the carton, but would have a precipitate
with the liquid
11. What is the major difference between a physical change and a chemical change?
a chemical change makes something completely different with different properties
12. Why is being flammable a chemical property rather than a physical property? because burning would
make something different with new and different properties