Precision, Accuracy and Measurements

Today we began by turning in our "What Chemical Reaction Labs."  We received our quizzes back and went over the problems.  Then Takashi, Chris, and Rachel played a game of darts.  The whole point of the game was to understand precision and accuracy.


Precision measures the reproducibility of your value.  In other terms precision means: how often can you get the intended outcome.  For example, in labs we want our results to be reproducible (the results should be the same each time).


Accuracy is the extent to which a measurement approaches the true value.  It is how close you are to the theoretical target (in this case the bulls eye).


We went over and took notes on precision, accuracy, and measurements.  In class we will be using the SI system which is based on the metric system.  Mass in grams (g), length in meters (m), and volume in liters (L) are the base units.  You will need to know how to convert different units.  The metric system is based on factors of 10 so it shouldn't be too complicated but if you need help here is a chart that may be useful. 

Factor	Prefix	Abbreviation
10 6	mega	M
103	kilo	k
10-1	deci	d
10-2	centi	c
10-3	milli	m
10-6	micro	µ
10-9	nano	n
10-12	pico	p

In the next class we will finish up our notes and cover temperature, significant figures, and scientific notation.  The homework is:
-Webassign 1.3 (due tomorrow if not already finished)
-Metrics worksheet 
-Study for quiz on Wednesday (Measurements, conversions)


The next scribe will be Chris A.  


Good luck!