1. Chapter 5
Section 2

2. A Complete Description
Chemical Properties 2
A Complete Description
A description of something using only physical properties is not complete. Chemical properties describe how matter behaves.

3. Common Chemical Properties2
Common Chemical Properties
The ability to burn is a chemical property.
A chemical property is a characteristic of matter that allows it to change to a different type of matter.

4. Common Chemical Properties2
Common Chemical Properties
You see an example of a chemical property when you leave a half-eaten apple on your desk, and the exposed part turns brown.
The property you observe is the ability to react with the oxygen.

5. Chemical Properties 2
Choosing Materials
Iron rusts easily because of its high reactivity (ree ak TIH vuh tee) with oxygen and moisture in the air.
Reactivity is how easily one thing reacts with something else.
The low reactivity of silver and gold, in addition to their desirable physical properties, makes those metals good choices for jewelry.

6. Chemical Properties and Pools2
Chemical Properties and Pools
The "chlorine" added to swimming pools is actually a compound called hypochlorous acid, which forms when chlorine reacts with water.
This acid kills bacteria, insects, algae, and plants.
Hypochlorous acid can cause problems as well.
It combines with nitrogen in the pool to form chloramines which can irritate the skin and eyes of swimmers.

7. Chemical Properties of Acids and Bases2
Chemical Properties of Acids and Bases
The chemical properties of acids and bases
are what make them both useful but sometimes harmful.

8. Acids 2 Many acids react with, or corrode, certain metals.
Chemical Properties 2
Acids
Many acids react with, or corrode, certain metals.
The acids in tomato sauce, oranges, carbonated soft drinks, and other foods are edible.
However, many acids can damage plant and animal tissue.
Small amounts of nitric (NI trihk) acid and sulfuric (sul FYOOR ihk) acid are found in rain.

9. Bases 2 A strong base is as dangerous as a strong acid.
Chemical Properties 2
Bases
A strong base is as dangerous as a strong acid.
A base such as sodium hydroxide (hi DRAHK side) can damage living tissue.
Ammonia feels slippery to the touch because the base reacts with the proteins in the tissues on your fingertips, which results in damaged tissue.

10. Chemical Properties 2
Salts
Acids and bases often are studied together because they react with each other to form water and other useful compounds called salts.
Salts are compounds made of a metal and nonmetal that are formed when acids and bases react.

11. Chemical Properties 2
Salts
Table salt, sodium chloride, can be formed by the reaction between the base sodium hydroxide and hydrochloric acid.
Other useful salts are calcium carbonate, which is chalk, and ammonium chloride, which is used in some types of batteries.

12. Section Check 2
Question 1
A _______ is a characteristic of matter that allows it to change to a different type of matter.
Answer
The answer is chemical property. Rotting fruit displays a certain chemical property, in this case, the ability to react with the oxygen air.

13. Section Check 2
Question 2
What is the term used to describe how easily one substance reacts with another substance?
A. activity
B. conductivity
C. flammability
D. reactivity

14. Section Check 2
Answer
The answer is D. Iron is highly reactive. When left outside it rusts, which shows reactivity with water and air.

15. Section Check 2
Question 3
Acids and bases react together to form compounds known as _______.
Answer
The answer is salts. Though we may think of salt as only applying to table salt, there are other kinds of salts.