Name _________________________
Chapter 1 homework
1 point each
1. Should an experiment test only one variable at a time? Why or why not?
a. Yes, because otherwise the variables could be confused with the control.
b. Yes, so that the experimental outcome is clearly due to one identifiable
variable.
c. No, because it takes much longer to do an experiment if you change only
one variable at a time.
d. As long as the experiment is repeated a sufficient number of times, it
doesn't matter.
e. No, but only if each variable can be measured as a separate observation.
2. In science, a hypothesis is only useful if
a. It can be proven correct
b. It can be proven incorrect
c. It can be tested
d. The explanation is already known
e. It includes only a prediction
3. Explain the difference between an autotroph and a heterotroph.
4. The best method for determining whether bean plants require sodium is to _____.
a. measure the amount of sodium in a few bean plants
b. measure how fast radioactive sodium enters the plant
c. look for sodium in leaf tissues using autoradiography
d. analyze root contents for sodium
e. grow bean plants with and without sodium
5. Local farmers think that a commonly used pesticide is responsible for the increase
in appearance of frogs with an additional appendage. To test this hypothesis, frogs
are injected with a small amount of pesticide mixed in ethanol. The frogs are
allowed to produce offspring to test the effect of the pesticide. Which of the
following would be the best controlled experiment?
a. One group is injected with pesticide.
b. One group is injected with pesticide, and one group is not injected with
anything.
c. One group is injected with ethanol, one group is injected with pesticide,
and one group is not injected with anything.
d. One group is injected with ethanol, and one group is injected with
pesticide.
6. A _______________ variable is the variable that is measured whereas the
______________ variable is the variable that is manipulated.
7. Explain what “emergent properties” are and give an example
8. “All the flowers are you see outside are pink therefore all flowers are pink” is an
example of _________ reasoning
a. Deductive
b. Inductive
c. Illogical
d. Circular
9. Rewrite the following statements into a testable hypothesis (1/3 point each, 1
point total)
***Remember to include the relationship between the things that you are testing:
Example: If the depth at which you are fishing affects the type of fish that are
caught than fishing at a deep depth will catch bottom fish.
a. Temperature causes leaf color to change
b. Students who read the chapter before class perform better in class
c. Chocolate causes pimples
10. How can sampling error influence an experiment?
Chapter 2 homework (1 point each)
1. If an atom contains 11 protons and 12 neutrons, its atomic number is
a. 1
b. 11
c. 12
d. 23
2. A solution of pH 6 contains ____ than the same of amount of solution at pH 8
a. 2 times more H+
b. 4 times more H+
c. 100 times more H+
d. 4 times less H+
e. 100 times less H+
3. In a group of water molecules, hydrogen bonds form between _____.
a. two hydrogen atoms in different water molecules
b. the oxygen atoms in different water molecules
c. the oxygen atom in one molecule and a hydrogen atom in another
molecule
d. the hydrogen atoms in a single water molecule
e. the oxygen atoms in a single water molecule
4. The atoms in the molecule of water shown below are held together by which type
of bond?
a.
b.
c.
d.
e.
hydrogen bond
ionic bond
polar covalent bond
nonpolar covalent bond
cohesive bond
5. Which of the following if a use of a radioactive isotope?
a. Can determine the age of rocks and fossils
b. Can be used to treat cancer and kill bacteria that spoil food
c. Used as tracers to follow movements of substances within organisms
d. Can be used to help diagnose medical problems
e. All of the above
6. Isotopes are atoms of the same element with the same number of protons and
a. Different number of electrons
b. Different number of molecules
c. Different number of neutrons
d. Same number of neutrons
7. You've made a hot drink by dissolving a teaspoon of instant coffee and a teaspoon
of sugar in a cup of hot water.
a. What kind of solution is this?
b. Identify the solute and solvent
8. A proton has a __________ charge and is found in the __________________. A
neutron has a ______________ charge and is found in the ________________.
An electron has a _________________ charge and is found in the ____________.
9. How are ionic bonds formed?
10. Explain why ice floats on top of water.