Lesson Summary
· The goal of science is to ask and answer testable questions.
· Scientists use a sequence of logical steps, called the
scientific method, which involves making observations, forming a hypothesis,
testing that hypothesis, and forming a conclusion.
· Physical, conceptual, and mathematical models help scientists to
discuss and understand scientific information and concepts.
· A scientific theory is a hypothesis that has been repeatedly
tested and has not been proven false.
· Safety in the laboratory as well as in the field are essential
components of good scientific investigations.
Review Questions
1. Write a list of five interesting scientific questions. Is each
one testable?
2. A scientist was studying the effects of oil contamination on
ocean seaweed. He thought that oil runoff from storm drains would keep seaweed
from growing normally, so he decided to do an experiment. He filled two
aquarium tanks of equal size with water and monitored the dissolved oxygen and
temperature in each to be sure that they were equal. He introduced some motor
oil into one tank and then measured the growth of seaweed in each tank. In the
tank with no oil, the average growth was 2.57 cm. The average growth of the
seaweed in the tank with oil was 2.37 cm. Based on this experiment:
1. What was the question that the scientist started with?
2. What was his hypothesis?
3. Identify the independent variable, the dependent variable, and
the experimental control(s).
4. What did the data show?
5. Can he be certain of his conclusion? How can he make his
conclusion firmer?
3. Explain three types of scientific models. What is one advantage
and one disadvantage of each?
4. Identify or design five of your own safety symbols, based on
your knowledge of safety procedures in a science laboratory.
5. Design your own experiment based on one of your questions from
question 1 above. Include the question, hypothesis, independent and dependent variables,
and safety precautions. You may want to work with your teacher or a group.
Points to Consider
· What types of models have you had experience with? What did you
learn from them?
· What situations are both necessary and dangerous for scientists
to study?
· What precautions do you think they should use when they study
them?
· How does the scientific meaning of the word theory differ from
the common usage? Can you find an example in the media of where the word was
used incorrectly in a scientific story? The misuse of the word theory is
rampant in the media and in daily life.