observed hypothesis

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Chp 1 and 2 Study Guide
1. Identify the activity that belongs in the field of chemistry.
a. developing medicines
b. analysis of a compound
c. production of a new plastic
d. all of the above
2. Which of these chemicals is definitely inorganic?
a. one that is made of carbon and hydrogen
b. one that is made of nitrogen and carbon
c. one that is made of nitrogen and hydrogen
d. one that is made of carbon and oxygen
3. A hypothesis is
a. an observation recorded from an experiment.
b. A proposed explanation for what is observed.
c. a summary of the results of many experiments.
d. A well-tested explanation for many observations.
4. Which of the following is not a part of the scientific method?
a. experimenting
b. proving
c. observing
d. hypothesizing
5. Identify the false statement.
a. A scientific law fully explains a set of observations.
b. The scientific method is a logical, systematic approach to the solution of a
problem.
c. For the results of an experiment to be accepted, the experiment must produce
the same results no matter how many times it is repeated.
d. The scientific method is repeated until a hypothesis either fits all the observed
experimental results or the hypothesis is discarded.
6. Which of these steps of the scientific method involves stating a relationship but
not proposing an explanation for the relationship?
a. observation b. theory c. scientific law d. hypothesis
Chp 1 and 2 Study Guide
7. Which of the following tasks would probably not be assigned to an analytical
chemist?
a. Determine the amount of copper in a sample.
b. Determine the amount of lead in a blood sample.
c. Determine the least expensive method to produce nylon.
d. Determine the amount of pollutants in a local lake.
8. Which of the following would most likely be an organic substance?
a. a chemical containing oxygen
b. a chemical containing carbon
c. a chemical containing hydrogen
d. a chemical containing nitrogen
9. A biochemist might:
a. determine the amount of energy released when a fossil fuel burns.
b. design a method to speed up the production of a metal from its ore.
c. identify the genes that control the production of insulin.
d. determine how much table salt will dissolve in a liter of water.
10. Because the worldwide demand for energy is growing, chemists are working to
a. find new sources of energy.
b. develop new ways of conserving energy.
c. develop new batteries for electric cars.
d. all of the above
11. A well-tested explanation for a broad set of observations is
a. a hypothesis.
b. a theory.
c. an experiment.
d. a scientific law.
12. To which of the following might a hypothesis be elevated after repeated
experimentation?
a. observation
b. theory
c. scientific law
d. experiment
13. Your friend makes the statement that “Water boils at a higher temperature
Chp 1 and 2 Study Guide
than ethanol.” How would you classify this statement?
a. observation
b. theory
c. scientific law
d. experiment
14. All of the following are general characteristics of liquids except
a. definite volume. c. not easily compressed. b. able to flow. d. definite
shape.
15. In the chemical reaction iron + oxygen  iron oxide,
a. iron oxide is a reactant.
b. oxygen is a product.
c. iron is a reactant.
d. iron is a product.
16) The chemical symbol for sodium is
a. NA.
b. SO.
c. Na.
D. So.
17) A basketball has more mass than a golf ball because:
a. the basketball takes up more space.
b. the basketball contains more matter.
c. the golf ball contains a different kind of matter.
d. the golf ball has an indefinite composition.
18) A gas is a form of matter that
a. has a definite volume.
b. is generally a liquid or solid at room temperature.
c. takes the shape and volume of its container.
d. is difficult to compress.
19) Homogeneous mixtures
a. are always liquids.
b. consist of two or more phases.
c. have a composition that is fixed.
d. are known as solutions.
20) A compound
a. is a pure substance.
b. has a composition that varies.
c. can be physically separated.
d. has properties similar to those of its elements.
21) When iron and oxygen combine to form iron oxide,
Chp 1 and 2 Study Guide
a. a physical change occurs.
b. a change in mass occurs.
c. a change of state occurs.
d. a chemical change occurs.
22) Which of the following is a physical property?
a. boiling point
b. freezing point
c. hardness
d. all of the above
23) Which of the following statements describes a solid?
a. It takes the shape of its container.
b. It takes the volume of its container.
c. Its particles are packed together tightly.
d. It is easily compressed.
24) Which of the following is an example of a physical change?
a. toasting bread
c. cooking a hamburger
b. digesting a banana
d. melting butter
25) An example of a heterogeneous mixture would be
a. sugar.
b. salt water.
c. tap water.
d. vegetable soup.
26) Which of the following is a compound?
a. carbon
b. hydrogen
c. oxygen
d. water
27) Iron is an example of a(n)
a. element.
b. compound.
c. heterogeneous mixture. d. homogeneous mixture
28) Which of the following is an example of a chemical change?
a. cooking meat
c. slicing cheese
b. dissolving sugar in iced tea
d. freezing water
Chp 1 and 2 Study Guide
Fill In The Blank
physical
29) A
property is a quality of a substance that
can be observed or measured without changing the composition
of the substance.
30) Elements combine chemically to form
compounds
.
homogeneous
31) A
mixture has a uniform composition throughout.
32) In any physical or chemical change, mass is
conserved .
33. A
liquid
 is a form of matter that flows, has a
fixed volume, and takes the shape of its container.
34. A
vapor
is a gaseous substance that is generally a liquid
or solid at room temperature.
35. A tossed green salad is an example of a
heterogeneous
36. The burning of wood is an example of a
chemical change.
37. The evaporation of water is an example of a
physical
change.
True or False
T
38. In a chemical reaction, mass is neither created nor destroyed; it is
conserved.
__F__39. Dissolving salt in water is a chemical change.
__T/F__40. Physical changes are not easily reversed.
_F_ 41. Elements can be separated into simpler substances by chemical reactions.
Matching
Chp 1 and 2 Study Guide
Column A
H
1) product
Column B
A) matter that flows but has a definite volume
F
2) physical change
B) amount of matter that an object contains
A
3) liquid
C) starting substance in a chemical reaction
B
4) mass
D) homogeneous mixture
E
5) element
G
6) solid
E) the simplest form of matter with a unique set of
properties
D
7) solution
F) alters a substance without changing its
composition
I
8) compound
G) matter with a definite shape and volume
C
9) reactant
H) substance formed in a chemical reaction
I) contains two or more elements chemically
combined in a fixed proportion
Column A
D 1) a physical blend of two or more components
E 2) a substance that can be separated into
simpler substances only by chemical means
B 3) doesn’t depend on amount present
A 4) matter that takes both the shape and the
volume of its container
C 5) depends on the amount present.
Column B
a.
gas
b.
intensive property
c.
extensive property
d.
mixture
e.
compound
Chp 1 and 2 Study Guide
Short Answer / Essay
1. Define chemistry.
2. List the major steps in the scientific method and describe each briefly.
3. List the five traditional branches of chemistry and explain what each involves.
4. You notice that a lawn looks unhealthy and that, perhaps, the grass is dying.
Chp 1 and 2 Study Guide
Undertake a scientific project to save the lawn.
a. What is your initial hypothesis, and what experiments can you design to test it?
b. Often in science you must try several ideas before you find a solution to a
problem. Suppose your hypothesis in part a is incorrect. Propose an alternative
hypothesis. Design a new experiment to test this hypothesis.
5. Distinguish between physical changes and chemical changes and give two
examples of each.
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