SaulloEnvironmental Science SCIENCE SKILLS Safety Science Tools Steps

Saullo-Environmental Science SCIENCE SKILLS

Safety

Science Tools

Steps of the Scientific Method 1. Problem State the _________ in the form of a question. �Example: What type of additive will make ice melt the fastest? 2. Research ________ the topic by using a variety of different resources. Try to answer the question before you begin.

Hypothesis 3. Develop a _________________ �Different from a prediction because it is testable �“If…. then…” statements work the best �Must include the independent and dependent variables of the experiment Manipulated variable ○ Independent variable: _________________ Responding variable ○ Dependent variable: _________________ ○ If (independent), then (dependent) If I do this, then this will happen. ○ Example: If salt, sugar, sand pepper are placed on ice separately, then salt will make the ice melt at the fastest rate.

experiment � Design and perform an __________ Control �Must include a ______ group along with several experimental groups ○ A control group contains all the controlled variables or constants ____________ but lacks the independent variables ○ A control group’s purpose is to show what would happen if nothing was manipulated. It is there for comparison. �Several trials will validate results and provide evidence of erred data. �Example: Ice would be allowed to melt on its own with no additives for a control group. The same size ice cube would be used for all groups (constant). All ice cubes (additives or none) would be allowed to melt in the same location (constant). Each additive would be tested 3 or 4 times and an average would be calculated.

Analyze � _______ results trends �Look for ______ in the data �Do not ignore any data…. you will bias introduce ____ Graphs �______ help an experimenter analyze results by providing a visual representation of data.

�Different types of graphs are used for different sets of data ○ Line graphs are used to show one variable relates to the other variable � always used if time is involved � if both variables are numerical values � Direct relationship: if one goes up, the other goes up � Indirect relationship: If one goes up, the other goes down ○ Bar graphs are used when data is collected by counting ________________ � If only one variable is a numerical value

� conclusion State a ____________________ � Restate hypothesis Accept Reject � ___________ or ____________ the hypothesis � Provide evidence from the data to backup your decision of acceptance or rejection. � Use background research to verify why the results turned out the way they did � State possible errors in collection of data or in procedural process � Example: I accept the hypothesis that the addition of salt to ice allowed it to melt at a faster rate than sugar, sand or pepper. The data showed that salt made the ice melt on average in 10 seconds versus the 30 seconds when sugar was added, the 20 seconds when sand was added, the 35 seconds when pepper was added and the 25 seconds when no additive was added. According to my research, salt was supposed to increase the melting time of ice due to it’s ability to dissociate into several particles and disrupts water’s ability to crystallize. It is possible that the data is erred based on the subjective (biased) nature of the actual melting of the ice cube.