Presentation on theme: "Introduction to Chemistry"— Presentation transcript:
1Introduction to Chemistry Chapter 1Introduction to Chemistry
2What is Chemistry?The study of the matter, its composition, properties, and the changes it undergoes.Applied chemistry is the using chemistry to attain certain goals, in fields like medicine, agriculture, and manufacturingPure chemistry gathers knowledge for knowledge’s sake
3Which 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
4Branches 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
5Why study Chemistry Explain the natural world Why? Prepare for a careerDirectly- in a labIndirectly- problem solving and thinking skillsBe an informed citizenVoteDon’t get scammed
6Applied Chemistry Material Design Plastics Paints Nanotechnology Scale Macroscopic- Big enough to seeMicroscopic- Too small to see unaidedNanotechnology- manipulating individual atoms and molecules
7Applied Chemistry Energy Ability to do work Different types can be converted to each otherConservationMore efficient conversionInsulationProduction –new sourcesStorage- batteries, fuel cells
8Applied Chemistry Agriculture Production- fertilizers, soil tests Protection – pesticide, herbicideMedicineDrugsMaterials- hips, artificial skinBiotechnology- using organisms as a means of production
9Applied Chemistry Environment- Pollution Eliminate sources Treatment once pollutedAstronomyRemote analysis of stars from their lightAnalysis of extraterrestrial samples
10Alchemy Forerunner of chemistry Mystical- search for perfection Practical- developed glassware and techniques used todayTried to change elementsFaulty assumptions and lack of logic led them astray
11Scientific Method A way of solving problems or answering questions. Starts with observation- noting an recording factsHypothesis- a possible explanation as to the cause of the observation, based on research and previous knowledge
12Scientific Method Experiment- designed to test the hypothesis only two possible answershypothesis is righthypothesis is wrongGenerates data -observations from experiments.Modify hypothesis - repeat the cycle
13VariablesControlled experiment- Only want one thing to change at a time in a laboratory.Manipulated variable- What you change or control directlyAlso called independent variableResponding variable – What changes as a result. No direct controlAlso called dependent variable
14Cycle 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
15Theory can never be proven. It is the best explanationUseful because they predict behaviorHelp us form mental pictures of processes (models)ObservationsHypothesisExperiment
16Another outcome is that certain behavior is repeated many times Scientific Law is developedDescription of how things behaveUsually an equationLaw - howTheory- whyObservationsHypothesisExperiment
17Law Modify Observations Theory (Model) Hypothesis Experiment PredictionModifyExperimentLawExperiment
18Communication Use Journals Do research Write article Describe procedures, methods, and findingsSubmit for peer reviewSent back for editingPublishLetters to editor respond.
19Collaboration Working together Teams Different skills Different specialtiesInternet andConferences
20Problem Solving Only way to get good is to practice Two parts Developing Plan-Hard partHigher level thinkingImplementing Plan-Not so hardApplication level
21Solving Numeric Problems Three steps-AnalyzeKnownNumbersMeasurementsEquationsUnknownWhat are you looking for?What units?
22Solving Numeric Problems Three steps-AnalyzePlanThe heart of problem solvingDiagramLook infoTableGraphEquation
23Solving Numeric Problems Three steps-AnalyzeCalculateEasiest partConvert measurementsRearrangeAppendix C
24Solving Numeric Problems Three steps-AnalyzeCalculateEvaluateReasonable?Read the question, did you answer it?Check your workEstimate
25PracticeWhat is the length, in centimeters, of a 10.0-inch ruler, given that there are 2.54 centimeters per inch?
26PracticeA certain ball when dropped from any height, bounces one-half the original height. If the ball was dropped from a height of 60 in. and allowed to bounce freely, what is the total distance the ball has traveled when it hits the ground for the third time? Assume the ball bounces straight up and down.
27Conceptual Problems Without numbers or math Two steps Analyze Identify known and unknownPlanSolve
28PracticeYou find a sealed box with strings protruding from three holes, as shown in the diagram. When you tug string A, it becomes longer and string C becomes shorter. When you tug string B, it becomes longer, but strings A and C are not affected. Make a diagram showing the arrangement of the strings inside the box.