Introducion to Chemistry What is chemistry? the study of the properties and behavior of matter physical and chemical properties of matter how different forms of matter change and interact the energy associated with chemical and physical changes

What is Matter? matter is anything that has mass and takes up space over 100 elements are the building blocks of matter an atom is the smallest particle of an element that retains the properties of that element atoms combine to form compounds, molecules and formula units

What is Non-Matter? Energy! Einstein gave us the idea that energy and matter are related E = mc 2

Why is it important to study chemistry? Chemistry acts as a sort of backbone for all of the other sciences. Advances in chemistry contribute to: virtually every aspect of our everyday lives, including, but not limited to:

Why is it important to study chemistry? the development of new medicines conservation of natural resources clean-up of the environment food production nutrition manufacture of goods….EVERYTHING

Scientific World View Some tenets of the scientific world view include: the world is understandable scientific ideas are subject to change scientific knowledge is durable science cannot provide complete answers to all questions

Scientific Inquiry All science demands evidence, but scientists differ in the type of evidence they rely on and how they go about answering questions. qualitative observations vs. quantitative measurements natural settings vs. controlled laboratory experiments passive vs. active Despite differences in technique and approach, there is general agreement about what constitutes an investigation that is scientifically valid.

Scientific Inquiry Process Skills 1.Questioning –Formulating Questions –Defining Problem Statements –Recognizing limits to the investigation 2.Proposing Ideas –Hypothesizing (Predictions) –Use background information

Scientific Inquiry Process Skills 3.Designing Experiments –Controlling variables –Determining Procedures –Evaluate experimental design 4.Gathering data –Observing –Measuring –Making data tables –Recording data

Scientific Inquiry Process Skills 5.Processing data –Organizing and presenting data –Manipulating data (calculating or graphing) –Determining experimental error % error or % yield

Scientific Inquiry Process Skills 6.Interpreting Data –Determine if your hypothesis was supported or not –Generating explanations, theories and models –Determine patterns or trends –Identifying the limits to the interpretation –Generating further ideas for experimentation

Questioning Proposing ideas Designing experiments Processing data Gathering data Interpreting data

Experimental Design Laboratories allow scientists to control their experiments so observations are reproducible. EXAMPLE: Francisco Redi’s Maggot Farm-1600s

Francisco Redi’s Maggot Farm— 17th Century In the 1600’s it was widely believed that living things could arise spontaneously from non-living, dead, or waste materials (this is called spontaneous generation), because people saw such materials "generate" living things such as mold or maggots.

Francisco Redi’s Maggot Farm— 17th Century In 1688, Italian naturalist Francisco Redi set out to test the idea with decaying meat in two containers: one open to the air, the other sealed. The open container meat eventually became infested with maggots.

Francisco Redi’s Maggot Farm— 17th Century

And when critics insisted that it was the sealing of the second container that kept spontaneous generation from occurring, Redi did the test with an open container and one covered with cheesecloth, through which air could circulate, and the cheesecloth- covered sample produced no maggots.

Francisco Redi’s Maggot Farm— 17th Century Source:

Variables- Good experiments are controlled. 1. Manipulated variable (independent variable) – Redi’s experiment –

Variables- Good experiments are controlled. 2. Responding variable (dependent variable)- Redi’s experiment-

Variables- Good experiments are controlled. 3. Controlled variables (constants)- Redi’s Experiment-

Problem statement: What is the effect of increasing the frequency of teeth brushing on the amount of plaque build-up? MV: RV: CV’s:

Metrics and Measurement Shift to the Student notes for “METRICS AND MEASUREMENT”