 Measurement, Sig Figs, and the Metric Systme Chemistry GT 9/4/14

Drill  Get “Significant Digits” half-sheet and fill out.  Put HW on desk.

Objectives  IWBAT  Measure with precision.  Explain the rules for significant figures.  Perform calculations correctly, using sig figs.

Let’s review the HW  Significant Figures WS

Measurement Lab, Part II  Make sure you are taking your measurements with a high degree of precision.  Record the number of sig figs in the third column

Metric System  Pick up packet!  Use the WS “Metric System Warm Up/ Exit Ticket”  Estimate the mass, volume, and length of various objects.  Complete ONLY Column 1!!!!!

The Measurement System of Science  Do these mean anything to you?  Kilo:  kilometer, kilogram  Centi:  centimeter, cents, century  Deca  Decathlon, decade

Brainstorm  What other metric units/prefixes do you know?  Let’s make a list!

Base Units  The International System (SI -- Le Système International d’Unités) has seven base units:  Length (meter - m)  Mass (kilogram - kg)  Time (second - s)  Amount of a substance (mole - mol)  Temperature (kelvin - K)  Electric Current (ampere - A)  Luminous Intensity (candela - cd)  ADD Volume (liter – L) – not really an SI unit!

Prefixes – give meaning!  There are eight prefixes that you will need to know for the SI units: Abbrev.  Mega (1,000,000 x base;M 1 mega-base = base)  kilo (1000 x base; 1 kilo-base = 1000 base) k  hecta (100 x base; 1 hecta-base = 100 base) h  deka (10 x base; 1 deka-base = 10 base) da  deci (base/10; 10 deci-base = 1 base) d  centi (base/100; 100 centi-base = 1 base) c  milli (base/1000; 1000 milli-base = 1 base) m  micro (base/ ;  /u micro-base = 1 base)

So what? How do we use them?  Any SI unit has two parts:  prefix  base  For example,  kilo - gram  kilo - mete r  centi - meter  centi - gram  So, what do we call 10 grams?  deca - gram  What do we call.001 seconds?  milli - second  How about.1 liters?  deci - liter

So, what?  Brainstorm an item (any item) that has, approximately:  mass of one gram  volume of one liter  time of one second  distance of one kilometer  FYI, 1 km = 0.62 mi, 1 kg = 2.2 lb

Closure  Your group will need a copy of the Animal Sort Chart.  You will be sorting the animals into categories based on the mass of the animals.  Sort the animals into the following categories:  category 1< 1 Kg  category 21 – 100 Kg  category 3101 – 1000 Kg  category 4> 1001 Kg  After everyone has sorted all of the animals into categories, we will have a class discussion.