The Nature of Science

Lab Safety Read your safety contract and know it well There are also some symbols used to describe hazards in the lab:

Scientific Method Identify a Problem Create a Hypothesis Perform an Experiment Collect and Analyze the Data Draw Conclusions Sometimes a 6th step is included in which you share your conclusions with others

Hypothesis vs. Theory vs. Law Hypothesis – An educated guess Scientific Theory – A hypothesis supported by many experiments Scientific Law- facts of nature accepted as truth

Controlled Experiments A Controlled Experment is one where only one variable is tested at a time Why is it important to use controlled experiments?

Controlled Experiments Control Group – the group that doesn’t receive the experimental treatment, a standard for comparison Independent Variable – the variable in the experiment you change Dependent Variable – the variable in the experiment that only changes because you changed the independent variable

Controlled Experiments Example: Merck decides to test a new antibiotic to see if it will cure patients’ sinus infections. Some testers are given pills containing the new antibiotic and others are given a placebo, or sugar pill. Identify: Control Independent Variable Dependent Variable

Qualitative vs Quantitative Data Qualitative Data – refers to data we observe without measuring such as color, shape, or texture Quantitative Data – refers to data that has numbers such as height, weight, or density

Chemistry Chemistry – the study of matter and the changes it undergoes Matter – anything with mass and volume Mass – the amount of matter in an object Weight – the effect of gravity on an object What is the difference between mass and weight? Chemistry deals with the submicroscopic world, or things that we cannot see with the naked eye or even a microscope

Chemistry There are 5 main branches of Chemistry Organic Chemistry – carbon containing compounds Inorganic Chemistry – the composition of matter that is not made up of organic compounds Biochemistry – processes of living things Analytical Chemistry – components and composition of substances Physical Chemistry – the energy changes related to chemical reactions

Unit 1 Test Lab Safety Lab Equipment Lab Techniques The Scientific Method Definitions relating to the Scientific Method What is Chemistry? Branches of Chemistry