July 28, 2015

Praxis II Chemistry, Physics, and General Science Test Questions

1. A student is working on a science project and is going through each step of the scientific method. After the student conducts his or her first experiment and records the results of the experimental test, what is the next step?
a. Communicate the results
b. Draw a conclusion
c. Repeat the experiment
d. Create a hypothesis

Use the following information to answer questions 2 and 3.

A student is conducting an experiment using a ball that is attached to the end of a string on a pendulum. The student pulls the ball back so that it is at an angle to its resting position. As the student releases the ball, it swings forward and backward. The student measures the time it takes the ball to make one complete period. A period is defined as the time it takes the ball to swing forward and back again to its starting position. This is repeated using different string lengths.

2. The student formed the following hypothesis:

Lengthening the string of the pendulum increases the time it takes the ball to make one complete period.

What correction would you have the student make to the hypothesis?
a. Turn it into an “if/then” statement.
b. Add the word “will” in the middle after the word “pendulum.”
c. Switch the order of the sentence so that the phrase about the period comes first, and the phrase about the string’s length is last.
d. No corrections are needed.

3. What would be an appropriate control variable for this experiment?
a. The period
b. The length of the string
c. The mass of the ball
d. The color of the ball

4. Once a hypothesis has been verified and accepted, it becomes a _________.
a. fact
b. law
c. conclusion
d. theory

5. A student has collected data on the width of tree trunks and average precipitation rates for different locations. The student wants to show the relationship between these two variables. What type of graph should be used?
a. A multi-line graph with the width measurements on the x-axis and precipitation rates on the y-axis.
b. A scatter plot with the width measurements on the y-axis and precipitation rates on the x-axis.
c. A bar graph with the width measurements on the y-axis and precipitation rates on the x-axis.
d. A pie chart with the width of tree shown as a percentage at different precipitation rates.

6. A student is measuring morning and afternoon temperatures for a school project using a thermal infrared gun instrument. The instrument is calibrated incorrectly and produces a cold bias of 7/10 of a degree in all the temperature measurements. How should the student deal with this error?
a. The student should recalibrate the instrument and redo the project.
b. Since it is not a major error, the student can ignore it.
c. This is a systematic error and the student should take it into consideration when analyzing the results by increasing the temperatures 7/10 of a degree.
d. This is a random error so the student should only mention it as a potential problem in interpreting the results.

7. Make the following metric conversion:
5 decimeters = ______ decameters

a. 0.5
b. 0.05
c. 50
d. 500

8. Which of the data sets could be plotted on a pie chart?
a. The total population of the top five largest U.S. cities.
b. The incubation period of a penguin colony as it relates to hours of daylight.
c. The distribution of weight among players of a football team.
d. The percent of vegetation cover and precipitation rates in different national parks.

9. Which of the following processes uses electrical charges to separate substances?
a. Spectrophotometry
b. Chromatography
c. Centrifugation
d. Electrophoresis

10. When using a light microscope, how is the total magnification determined?
a. By multiplying the ocular lens power times the objective being used.
b. By looking at the objective you are using only.
c. By looking at the ocular lens power only.
d. By multiplying the objective you are using times two.
Praxis II Chemistry, Physics, and General Science Test Answer Key