ChemistryChemistry

What is ChemistryWhat is Chemistry

~The science that deals with the materials ~The science that deals with the materials of the universe and the changes these of the universe and the changes these materials undergo.materials undergo.

The study of the interactions of matter The study of the interactions of matter (atoms and molecules) and the energy (atoms and molecules) and the energy involvedinvolved

Gathering InformationGathering Information

Observation- a fact you use one of your five Observation- a fact you use one of your five senses to determinesenses to determine

(the thermometer reads 24(the thermometer reads 24o o C, this font is C, this font is white)white)

Inference- something you reason outInference- something you reason out (Heat entered the liquid causing the (Heat entered the liquid causing the

temperature to rise)temperature to rise) Inferences are not as reliable as observations Inferences are not as reliable as observations

but sometimes required.but sometimes required.

Problem SolvingProblem Solving

1. Recognize some problem, and clearly 1. Recognize some problem, and clearly state it.state it.

2. Propose a possible solution to the 2. Propose a possible solution to the problem, this is formulating a hypothesis.problem, this is formulating a hypothesis.

3. Test your hypothesis by running some 3. Test your hypothesis by running some type of an experimenttype of an experiment

Scientific MethodScientific Method

~A procedure for solving problems~A procedure for solving problems Gather informationGather information Form a hypothesisForm a hypothesis Test your hypothesisTest your hypothesis Analyze your resultsAnalyze your results Draw conclusionDraw conclusion Repeat your work and share it with othersRepeat your work and share it with others

It is not an exact sequenceIt is not an exact sequence

Gather info

Form hypothesis

Test hypothesis

Analyze results

Draw conclusion

Repeat your workAnd share it with others

Problem

Using the Scientific MethodUsing the Scientific Method Gather infoGather info -I can’t wake up for school, I should -I can’t wake up for school, I should

research sleep pattern, diet, exercise etc.research sleep pattern, diet, exercise etc. Form a hypothesisForm a hypothesis (An educated guess on (An educated guess on

the solution of the problem)the solution of the problem) -If I go to bed earlier, then I will be able to -If I go to bed earlier, then I will be able to

wake up.wake up. Test your hypothesis Test your hypothesis This is the experiment This is the experiment

step step -try to go to bed earlier-try to go to bed earlier

ContinuingContinuing

Analyze your resultsAnalyze your results -check your results each day.-check your results each day. Draw conclusionDraw conclusion -If it worked you confirmed your -If it worked you confirmed your

hypothesis, if it didn’t you proved it wronghypothesis, if it didn’t you proved it wrong Repeat your work and share it with othersRepeat your work and share it with others Flukes happen always double check, and Flukes happen always double check, and

then tell someone about your discoverythen tell someone about your discovery

ExperimentExperiment There are many ways to experimentThere are many ways to experiment Variable- what you are testingVariable- what you are testing only test one variable at a timeonly test one variable at a time A control group is necessary for an accurate A control group is necessary for an accurate

comparison (the experiment without the variable)comparison (the experiment without the variable) BlindedBlinded control groups don’t know they are the control groups don’t know they are the

control control Double blindedDouble blinded studies have patients who don’t studies have patients who don’t

know they are the control and experimenters who know they are the control and experimenters who don’t know they are working with the controldon’t know they are working with the control

Theories and LawsTheories and Laws

After a hypothesis is tested several times it After a hypothesis is tested several times it is accepted or rejectedis accepted or rejected

Theory- attempts to explain Theory- attempts to explain whywhy these these hypotheses and observations are so.hypotheses and observations are so.

Law- summary of Law- summary of whatwhat is said in several is said in several hypotheses and observations.hypotheses and observations.

Theories do NOT become laws!Theories do NOT become laws!

ModelsModels Model- any representation of an object or a Model- any representation of an object or a

systemsystem A theory is sometimes called a model as it A theory is sometimes called a model as it

explains helps to explain how something works.explains helps to explain how something works. The theory or model of how a gas works would The theory or model of how a gas works would

be countless tiny particles (atoms and be countless tiny particles (atoms and molecules) moving about rapidly colliding with molecules) moving about rapidly colliding with everything.everything.

This is the best possible accepted account for This is the best possible accepted account for whywhy gas act the way they do. gas act the way they do.

LawsLaws

A Natural Law is a summary statement.A Natural Law is a summary statement. Like Charles’ Law, put simply, heating a Like Charles’ Law, put simply, heating a

gas makes it expand, cooling it makes it gas makes it expand, cooling it makes it contract.contract.

There is no There is no whywhy in a Law, just in a Law, just whatwhat happens.happens.

A law is A law is NOTNOT a more proven version of a a more proven version of a theory, it is a different type of a statement.theory, it is a different type of a statement.