Chapter 3, section 1: Elements
4. What physical changes can you make to a substance to determine if it’s an element?
A) Crushing
B) Grinding
C) Filtering
5. A pure substance that contains only one type of particle. TRUE
Example: Gold
6. In Figure 2, what do the skillet and meteorite have in common?
Both contain elements of Iron (Fe).
7. Characteristic properties of elements do NOT depend on the AMOUNT of material
present in a sample of the element. TRUE
8. Why does a Helium (He) balloon float up when it is released?
Helium is less dense than air.
9. Circle the characteristic properties:
Hardness
Melting point
Density
Flammability
Color
Reactivity with acid
10. Suppose you have a cube of Nickel (Ni) and a cube of Cobalt (Co), but you don’t
know which is which. How could you use characteristic properties in Figure 3 to figure
out which cube is Nickel and which is Cobalt?
Melt the cubes and compare their melting points. The cube that melts at 1,455
degrees Celsius is Nickel and 1,495 degrees Celsius is Cobalt.
11. What are some common properties that most terriers share? Answers may vary.
Ex: Terriers are small and have short hair.
12. Which of the following is a property that Nickel (Ni), Iron (Fe), and Cobalt (Co)
DON’T share? B) Poor conductivity of electric current
13. All elements can be classified as metals, metalloids, or nonmetals. TRUE
Classify for 14-23. A Metalloids
B Nonmetals
14. C Malleable
15. A Dull or shiny
16. B Poor conductors
17. B Tend to be brittle and unmalleable as solids
18. C Always shiny
19. A Semiconductors
20. B Graphite in pencils
21. B Always dull
22. A Used in computer chips
23. C Ductile
C Metals
Chapter 3, Section 2: Compounds
1. When two or more elements are chemically combined to form a new pure substance,
we call that new substance a compound.
2. A compound is different from the elements that reacted to form it. TRUE
3. List three examples of compounds you encounter every day.
Table salt, water, sugar, carbon dioxide, water, etc
4. Which of the following is NOT true about compounds?
C) Compounds are random combinations of elements.
5. Each compound has its own physical properties. TRUE
6. Compounds cannot be identified by their chemical means. FALSE
7. A compound has the same properties as the elements that form it. FALSE
8. Sodium and chlorine can be extremely dangerous in their elemental form. So how is
it possible that we can eat them in a compound?
A compound has different properties than the elements that form it. Although they
are dangerous individually, they combine to form sodium chloride. Sodium chloride
(also known as table salt) is harmless, dissolves in water, and is safe to eat.
9. What compound helps to give carbonated beverages their “fizz?” Carbonic Acid
Which elements make this compound?
Carbonic acid is made up of carbon, oxygen, and hydrogen.
10. A physical change is the only way to break down a compound. FALSE
11.
Look at the Physics Connection. The chemical process used to obtain industrial
products such as hydrogen peroxide is called electrolytes.
12.
Which of the following methods are used by living organisms to obtain nitrogen,
an element to make proteins?
B) Plants use nitrogen compounds in the soil.
C) Animals digest plants or animals that have eaten plants.
13. What do most fertilizers, food preservatives, and medicines have in common?
They are all manufactured compounds.
14. The compound aluminum oxide is broken down to produce the element used in cans,
airplanes, and building materials.
Chapter 3, Section 3: Mixtures
1. A pizza is not a mixture. FALSE
2. When two or more materials combine without reacting with each other, they form a
mixture. TRUE
3. How do granite in Figure 11 and the pizza at the top of the page show you the identity
of a substance doesn’t change in a mixture?
It’s possible to identify all of the components, or parts, in the granite and pizza. The
identity of the substance doesn’t change in a mixture.
4. Mixtures are separated through physical changes.
5. A
Crude Oil- distill the mixture
6. D
Aluminum & Iron- pass a magnet over mixture
7. B
Parts of blood- centrifuge the mixture
8. C
Sulfur & Water- filter the mixture
9. Granite can be pink or black, depending on the ratio of feldspar, mica, and quartz.
TRUE