Guided Reading Chapter 3 Section 2

  1. An experimentis a situation that is set up to investigate the relationships between variables.
  2. When experimenting, it is important to change onevariable(s) at a time.
  3. Explain the difference between the experimental variable and the control variables in an experiment.

Control variables are all of the things being kept the same. The experimental variable is the thing you change.

  1. Each time you run an experiment is called one trialand how you perform the experiment is called the experimental technique.
  2. Good scientists keep careful track of their procedures soother scientists can follow your method to (hopefully) repeat your results.
  3. A good lab report should containa research question, a hypothesis, experimental procedures, and data/conclusionsso that it clearly communicates the results of your experiment.
  4. What scientific question did NASA scientists investigate in 1996 during space shuttle mission STS-75?

What is the relationship between electricity and magnetism? Does Faraday’s experiment work in space?

  1. What was the result of the experiment that the NASA scientists conducted to investigate their question?

When cable connecting a space shuttle to a satellite was dragged through Earth’s magnetic field, an electrical charge was created on the cable (this is similar to how a car’s alternator charges the battery while the car is running).

Vocabulary Chapter 3 Section 2

Select the correct term to complete the sentences.

control variable

experiment

experimental technique

experimental variable

hypothesis

Model

procedure

scientific method

system

theory

trial

variable

  1. When you run an experiment multiple times, you conduct several trials.
  2. The thing you are testing (changing) in an experiment is the experimental variable.
  3. Something you keep the same from trial to trial in an experiment is called the control variable.
  4. A step-by-step account of all that you do when conducting a particular experiment is called the procedure.
  5. The way you release a car on a ramp while conducting an experiment is an example of experimental technique.
  6. A(n) experimentis a situation specifically set up to investigate relationships between variables.
  7. A modelis a representation of another thing that is used to support and/or demonstrate scientific theories
  8. A systemis a group of variables that are related in some way. It is the thing at which you are looking.
  9. A variableis any factor that affects an experiment.

Chapter 3 Section 2 Review

  1. Why is experimentation so important to science?

Experimentation helps to create an understanding of how our observations of the natural world are related to each other. It allows us to test our hypotheses and create scientific theories and natural laws.

  1. It is important, in an ideal, simple experiment, to change only one variable from trial to trial so that you know which variable is responsible for changes you observe in a system.
  2. Suppose you have three identical drinking cups: one made of plastic, onefoam, and one paper. You want to find out which cup will keep your hotcocoa hot for the longest time.
  3. Write a research question for this experiment.
    Which material will keep my hot cocoa hot for the longest time?
  4. What is your hypothesis?
    4 possible choices:
    1) The plastic cup will keep my cocoa hot the longest
    2) The paper cup will keep my cocoa hot the longest
    3) The foam cup will keep my cocoa hot the longest
    4) All 3 cups will keep cocoa hot the same amount of time
  5. What is the experimental variable?Material of the cup
  6. What are three important control variables?
    Amount of cocoa; starting temperature of the cocoa; size of the cup; temp of the room; brand of cocoa; shape of the cup
  7. What type of evidence will you collect to test your hypothesis?
    Time and Temperature
  8. Monique wants to see what happens when she drops a marble from different heights into a baking tray that has a thick layer of very soft modeling dough pressed inside. She predicts that the closer the marble is to the dough when she drops it, the deeper the indentation will be.
  9. What is Monique’s hypothesis?
    “The closer the marble is to the dough when she drops it, the deeper the indentation will be.”
  10. The experimental variable is the height of the marble when she drops it.
  11. What are two control variables?
    Size of the marble; type of dough; temperature of the dough; amount of dough; shape of dough (or container dough is in) before marble drop
  12. What is the evidence that will be collected?
    Depth of indent into the dough and height from which the marble was dropped.