Science & the Scientific Method What is science? Science is the use of evidence to construct testable explanations and predictions of natural phenomena as well as the knowledge generated through this process.

What is chemistry? Chemistry is the branch of science that studies matter and the changes it undergoes. -or- The branch of science that deals with the identification of substances of which matter is composed; the investigation of their properties and the ways they interact, combine, and change. Science & the Scientific Method

Branches of chemistry Physical chemistry - study of the physical and fundamental basis of chemical systems and processes (examples: thermodynamics, electrochemistry, astrochemistry) Organic chemistry – study of the structure, properties, composition, mechanisms, and reactions of organic compounds (compounds with a carbon backbone) Science & the Scientific Method

Branches of chemistry Inorganic chemistry – study of the properties and reactions of inorganic compounds. Includes nuclear chemistry. Analytical chemistry – analysis of material samples to gain an understanding of their chemical composition and structure

Science & the Scientific Method Branches of chemistry Biochemistry – study of the chemicals, reactions, and interactions that take place in living organisms. Petrochemistry – study of the transformation of petroleum and natural gas into useful products Phytochemistry – study of phytochemicals that come from plants

Science & the Scientific Method Branches of chemistry Agrochemistry – study and application of chemistry and biochemistry for agricultural production, food processing, and environmental monitoring. Pharmacology – branch of medicine and biology concerned with the study of drug action and their chemical effects

Scientific inquiry - the planned and deliberate investigation of the natural world. Scientific methods of investigation can be experimental, descriptive, or comparative. The method chosen should be appropriate to the question being asked. Science & the Scientific Method

Scientific system – collection of cycles, structures, and processes that interact. All systems have basic properties that can be described in terms of space, time, energy, and matter. Change and constancy occur in systems as patterns and can be observed, measured, and modeled. These patterns help to make predictions that can be scientifically tested. Science & the Scientific Method

What is the scientific method? The scientific method is the principles and procedures involving the recognition and formulation of a problem, the collection of data through observation and experiment, and the formulation and testing of hypotheses.

6 Steps of the Scientific Method 1.Make an observation. 2.Ask a question. 3.Formulate a hypothesis 4.Test hypothesis via experimentation 5.Analyze data and draw conclusions 6.Communicate & share your results Science & the Scientific Method

1.Make an observation. Some tomatoes in my garden are bigger than others. 2.Ask a question. Why are some tomatoes bigger than others? 3.Formulate a hypothesis. I think the tomatoes are bigger because those plants get more sun than others. Science & the Scientific Method

What is a hypothesis? Hypothesis - a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation. Hypotheses are tentative and testable statements that must be capable of being supported or not supported by observational evidence. What is the difference between a hypothesis and a theory? Science & the Scientific Method

A theory is a well-established principle that has been developed to explain some aspect of the natural world. A theory arises from repeated observation and testing and incorporates facts, laws, predictions, and tested hypotheses that are widely accepted. A hypothesis is a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation. Science & the Scientific Method

Hypotheses of durable explanatory power that have been tested over a wide variety of conditions are incorporated into theories Science & the Scientific Method

theories are based on natural and physical phenomena and are capable of being tested by multiple independent researchers. Unlike hypotheses, scientific theories are well- established and highly-reliable explanations, but may be subject to change as new areas of science and new technologies are developed Science & the Scientific Method

4. Test hypothesis via experimentation Experiment – a scientific test in which you perform a series of actions and carefully observe their effects in order to learn about something Science & the Scientific Method

Parts of an experiment variables - the factors that change during the experiment The independent variable is the variable that is intentionally changed in the experiment. Varying photoperiods for growth of tomatoes Science & the Scientific Method

The dependent variable is the variable that responds to the changes in the independent variable. The size of the tomatoes The control is the standard against which the researcher compares the results from each treatment group (level) in the experiment. Tomatoes in no light Science & the Scientific Method

Constants are the things that are kept the same each time one of the trials in the experiment is repeated. Fertilization or water for tomato plants The repeated trials are the number of times the experiment is repeated to determine how the independent variable affected the results. How many tomato plants were exposed to each photoperiod? Science & the Scientific Method

5. Analyze data and interpret the results Organize your data. Science & the Scientific Method

Graph your data and observe trends. Science & the Scientific Method

Which photoperiod had the largest tomatoes? Which photoperiod had the smallest? Analyze and interpret your results

Conclusion? 12 hour photoperiod gave the largest tomatoes. Do tomatoes tolerate no light very well? Do tomatoes tolerate nonstop light very well? Could other factors have affected the growth of tomatoes? Science & the Scientific Method