Chapter 1- start to finish Let’s Get Started!! Chapter 1- start to finish

CHEMISTRY The science that deals with the materials of the universe and the changes that these materials undergo Wood burns Plants grow Iron rusts Bread bakes Human digestion

The Scientific Method State the problem Make observations Form a hypothesis Perform an experiment Develop a Law A summary of observed behavior Develop a theory An explanation of behavior Continue to experiment Modify theory as needed

Important Terms Matter Mass Volume Qualitative observations Anything that has mass and volume Mass Amount of matter in an object The measure of the resistance of an object to a change in its state of motion Volume Amount of space an object occupies Qualitative observations Observations not requiring measurements Quantitative observations Observations requiring measurements

Weight!?! The force that gravity exerts In chem (or in AP) all our measurements will be on earth (we hope!) so weight & mass are interchangeable.

Volume?

Fundamental Units Mass Length Time Temp kg m s K

Fundamental Units Electric current Amt of substance Luminous intensity mol cd

Prefixes Used in SI system Kilo deci centi milli 103 10-1 10-2 10-3

Prefixes Used in SI system micro nano 10-6 10-9

Uncertainty of Measurement Gold costs $5.75 for .01 g Mass ring- 7.62 g Dealer says- 8 g

What’s the problem? The decimal places are SIGNIFICANT!!

Numbers are significant when… 1. They are NOT zero! 2. They are exact numbers Conversions, pi, counted numbers

Numbers are significant when… Zeros 1. Captive zeros- YES 2. Leading zeros- NO 3. Trailing zeros- YES

Multiply and Divide Number of sig figs in answer is same as number with least number of sig figs

Add and Subtract Result has same number of decimal places as number with least decimal places in calculation

Number of Sig Figs? 1056 1000 100.0 .00350 4 1 3

Some Math… 2.002 X 3.42 X 5 = 703.2+34.223–21.45 = 34.2 X 25.3 + 1.332 = 30 716.0 866

Play some darts…

Precision Degree of agreement among several measurements

Accuracy Degree of agreement of a particular value with the accepted value

Error?? What error? Random error Systematic error Equal chance of being high or low Systematic error Same direction each time

Dimensional Analysis UNIT FACTOR METHOD! A student entered a 12.0 km run. How many miles is it?

Temperature Three scales Fahrenheit Celsius Kelvin

Density Mass/Volume

Classification of matter

Physical and Chemical Properties and Changes Physical Property Characteristics that describe a substance Physical Change A change that does not affect the composition of the substance Chemical Property Characteristics that refer to the ability to form new substances Chemical Change A change which produces new substances

Separation Techniques Distillation Filtration Chromatography