Science Basics Getting a Handle on Some Terminology

Fact or Belief? Fact – specific statement about of substance or process that can be verified Ex. Sodium is a reactive metal. Sulfur is yellow. Iron rusts.

Fact or Belief? Belief – statement that may be true but cannot be verified at present Ex. All electrons look alike. The Sun will rise tomorrow. As scientific belief is based on substantial evidence that predicts a likely outcome or situation.

Law Law - generalized statement of a relationship between variables in a system based on repeated experimentation; can be used to predict behavior of a system Ex. As the temperature of a gas increases, its volume increases.

Hypothesis or Theory? Hypothesis – possible action and/or explanation for a behavior or an observation; must be tested through experimentation Ex. Increased temperature will speed up the dissolving of a salt in water.

Hypothesis or Theory? Theory – generalized explanation for observations based on repeated experimentation or observations; can sometimes be used for predictions Ex. Behavior such as expansion with heat or increased pressure with decreasing volume is a result of particles that are far apart and moving rapidly.

Scientific Method  Make an observation that raises a questionState a question  Determine a possible reason for the observation Pose a hypothesis  Design and carry out an investigation to prove or disprove the hypothesis Do an experiment

Scientific Method  Compile information from the experiment and decide if the hypothesis was correct Analyze/Make a conclusion  If the conclusion or experimental process raises other questions, start the process again.

Scientific Method Understand variables: – Independent variable = one changed by the experimenter – Dependent variable = one that changes as a result of a change in the independent variable – Controlled variable = any property that is not being investigated and must remain the same during the experiment

Scientific Method  Make an observation that raises a question. Do birds prefer red or blue bird feeders?  Determine a possible reason for the observation. Pose a hypothesis. Birds prefer red feeders.  Design and carry out an investigation to prove or disprove the hypothesis Determine the variables: Independent = color of the feeder Dependent = # of birds at the feeder

Scientific Method Determine the variables: Controlled = type of feeder, type of food, time of day recorded, height of feeder, location of feeder… Set up 3 blue and three red identical bird feeders. At a set time each day for 10 days, record how many birds are at each feeder. Record data in a suitable table.

Scientific Method  Compile information from the experiment. Analyze the data. Make a bar graph of the number of birds at each color feeder for each day.  Decide if the hypothesis was correct. Make a conclusion The birds prefer a red feeder over a blue feeder.