Presentation on theme: "Introduction to Chemistry Dr. Richard Malik"— Presentation transcript:
1 Introduction to Chemistry Dr. Richard Malik Chapter 1Introduction to ChemistryDr. Richard Malik
2 The Stories of Two Chemicals Ozone is formed when oxygen gas is exposed to ultraviolet radiation in the stratosphere forming an ozone layer.Ultraviolet radiation (UV) is harmful to plants and animals.Importance of the Ozone Layer:Ozone absorbs most of the harmful UV radiation before it reaches Earth’s surface.
3 The Stories of Two Chemicals Chlorofluorocarbons (CFC)Used as coolant for refrigeratorsUsed as propellants in spray cansCFC’s escape into the atmosphere causing a thinning of the ozone layer.
4 What is Chemistry?Chemistry is the study of the matter, its composition, properties, and the changes it undergoes.Applied chemistry is the using of chemistry to attain certain goals, in fields like medicine, agriculture, and manufacturingPure chemistry gathers knowledge for knowledge’s sake
5 Which Comes First? Pure Chemistry Applied Chemistry Usually comes first, applied laterCalled technologyOr engineeringPure chemistry can explain behavior that has been used without knowing whySteel swordsCan’t be good or badCan be good or bad depending on use
6 Mass and Matter?Matter is anything that has mass and takes up space. (Ex. Book)Mass is the amount of matter in an object. Measured in grams (g)Weight- The weight of an object is a measure of the force of gravity on the object.Your weight will change if you move from the North pole to the equator but our mass will stay the same.
7 Branches of ChemistryAnalytical Chemistry -studies composition of substances.Organic Chemistry -compounds containing carbonInorganic Chemistry -substances without carbonBiochemistry- Chemistry of living thingsPhysical Chemistry studies behavior of substancesrates and mechanisms of reactionsenergy transfers
8 Applied Chemistry Material Design Plastics Paints Nanotechnology Scale Macroscopic- Big enough to seeMicroscopic- Too small to see unaidedNanotechnology- manipulating individual atoms and molecules
9 Applied Chemistry Agriculture Production- fertilizers, soil tests Protection – pesticide, herbicideMedicineDrugsMaterials- hips, artificial skinBiotechnology- using organisms as a means of production
10 Scientific Method A way of solving problems or answering questions. Step 1:Observation- the act of gathering information. Observations can be:Qualitative data- Anything that relates to the five senses. (look, feel, sound, taste, smell)Quantitative data- Numerical information that tells you how much, how little, etc.
11 Scientific Method (cont.) Step 2:Hypothesis- a testable statement or prediction that explains the cause of the observation, based on research and previous knowledgeStep 3: Experiment- a process designed to test the hypothesis.only two possible answers, hypothesis is right or wrongGenerates data -observations from experiments.
12 Scientific Method (cont.) Step 4 Conclusion: A judgment based on the information obtained. Can lead to a theory.Theory - Hypothesis supported by many experiments.Scientific Law- Summary of accepted facts of nature.Step 5 Modify hypothesis - repeat the cycle.
13 Cycle repeats many times. By you and by othersThe hypothesis gets more and more certain.Becomes a theoryA thoroughly tested model that explains why things behave a certain way.ObservationsHypothesisExperiment
14 Theory can never be proven. It is the best explanationUseful because they predict behaviorHelp us form mental pictures of processes (models)ObservationsHypothesisExperiment
15 Another outcome is that certain behavior is repeated many times Scientific Law is developedDescription of how things behaveUsually an equationLaw - howTheory- whyObservationsHypothesisExperiment
16 Law Modify Observations Theory (Model) Hypothesis Experiment PredictionModifyExperimentLawExperiment
17 VariablesControlled experiment- Only want one thing to change at a time in a laboratory.Independent variable- What you change or control directly.Dependent variable – What changes as a result of changing the independent variable. No direct control.
18 ReferencesDingranso, L, Gregg, K, Hainen, N, & Wistrom, C (2002). Chemistry: matter and change. Columbus, OH: Glencoe/McGraw-Hill.Green, N.D., Mr. Green’s Home Page. Retrieved October 17, 2008 from