Measurement

We will be learning about how to measure accurately and precisely, how to determine our percent error in measurements, learn about the temperature scales and how to convert from one scale to another, how to use a math process called Dimensional Analysis to convert our units, and how to manipulate scientific notation in four ways (addition, subtraction, multiplication and division).

This measurement topic will not be easy, and to find real success, it will require you to do all of your homework when it is assigned.  

I cannot stress the importance of significant figures enough, they will count against you all year  (unless you learn them immediately).  



Read a thermometer to the CLOSEST temperature line, then ESTIMATE one place more.  This says 87.6 but not 87.55 degrees centigrade.
Never forget your significant figures, they are significant.
Three temperature scales, we will use ONLY centigrade and Kelvin.
K = C + 273   Use your formula always.

Accurate: measures close to correct.  Precise: measures close together (can be accurate or not).  Both accurate and precise: is what we want in chemistry measuring always.

Measure the meniscus properly as shown.  Estimate only ONE place after the closest line on the graduated cylinders.
When measuring with any tool that's NOT DIGITAL, only measure one place past the closest line.  This says 2.33 cm or maybe 2.35 cm, but NOT 2.3 cm or 2.4 cm.
The many zero rules of significant figures will make you bonkers unless you memorize them.  Just do it.
Never round a measuring tool that tells you the measuring, there is NO ESTIMATING with a digital scale.  You get the significant figures that you get.
When doing math in chemistry, always use a formula to avoid what can only be called dumb mistakes.  No one can help making errors, formulas will reduce your errors.  ALWAYS, always, use your units and make sure you cancel them as you go.