Summary Physical And Chemical Properties and Changes QUESTIONS and KEY ANSWERS

PHYSICAL AND CHEMICAL PROPERTIES AND CHANGES
Name _____Key_______________________


PHYSICAL PROPERTY CHEMICAL PROPERTY
1. observed with senses 1. indicates how a substance
2. determined without destroying matter reacts with something else
2. matter will be changed into a new
substance after the reaction


Identify the following as a chemical (C) or physical property (P):
______1. blue color ______8. melting point
______2. density ______ 9. reacts with water
______3. flammability (burns) ______10. hardness
______4. solubility (dissolves) ______11. boiling point
______5. reacts with acid ______12. luster
______6. supports combustion ______13. odor
______7. sour taste ______14. reacts with air


PHYSICAL CHANGE CHEMICAL CHANGE
1. a change in size, shape, or state 1. a change in the physical and
2. no new substance is formed chemical properties
2. a new substance is formed


Identify the following as physical (P) or chemical (C) changes.
_____1. NaCl (Table Salt) dissolves in water. ______9. Milk sours.
_____2. Ag (Silver) tarnishes. ______10. Sugar dissolves in water.
_____3. An apple is cut. ______11. Wood rots.
_____4. Heat changes H2O to steam. ______12. Pancakes cook.
_____5. Baking soda reacts to vinger. ______13. Grass grows.
_____6. Fe (Iron) rusts. ______14. A tire is inflated.
_____7. Alcohol evaporates . ______15. Food is digested.
_____8. Ice melts. ______16. Paper towel absorbs water.

Physical and Chem ical Changes
Part A
Can you recognize the chemical and physical changes that happen all around us? If you change the way
something looks, but haven’t made a new substance, a physical change (P) has occurred. If the substance
has been changes into another substance, a chemical change (C) has occurred.

1. An ice cube is placed in the sun. Later there is a puddle of water. Later still the puddle is gone.

2. Two chemical are mixed together and a gas is produce.

3. A bicycle changes color as it rusts.

4. A solid is crushed to a powder.

5. Two substances are mixed and light is produced.

6. A piece of ice melts and reacts with sodium.

, Part B
Read each scenario. Decide whether a physical or chemical change has occurred and give evidence for your
decision. The first one has been done for you to use as an example.
Physical or
Scenario Chemical Evidence…
Change?
Umm! A student removes a loaf of bread
1. hot from the oven. The student cuts a slice
off the loaf and spreads butter on it.
Your friend decides to toast a piece of
bread, but leaves it in the toaster too long.
2.
The bread is black and the kitchen if full of
smoke.
You forgot to dry the bread knife when you
3. washed it and reddish brown spots
appeared on it.


4. You blow dry your wet hair.

In baking biscuits and other quick breads,
the baking powder reacts to release carbon
5.
dioxide bubbles. The carbon dioxide
bubbles cause the dough to rise.
You take out your best silver spoons and
6. notice that they are very dull and have
some black spots.

A straight piece of wire is coiled to form a
7.
spring.


Food color is dropped into water to give it
8.
color.

Chewing food to break it down into smaller
particles represents a _________ change,
9. but the changing of starch into sugars by
enzymes in the digestive system represents
a ___________change.

In a fireworks show, the fireworks explode
10.
giving off heat and light.

Part C: True (T) or False (F)

1. Changing the size and shapes of pieces of wood would be a chemical change.

2. In a physical change, the makeup of matter is changed.

3. Evaporation occurs when liquid water changes into a gas.

4. Evaporation is a physical change.

5. Burning wood is a physical change.


6. Combining hydrogen and oxygen to make water is a physical change.