1. WARM UP 1.List 5 metric units, their symbol, and the quantity they measure. 2.Convert 4.5 g to ng

2. Chemistry and Math Chem II

3. Significant Figures Rules: –Start count at first non-zero number All numbers to the right are significant if a decimal point is present. If no decimal point, trailing zeroes are not significant Ex: 130.0400 vs. 140,000

4. Computations and Sig Figs Add/Subtract –Use fewest number of decimals Ex: 12.14 + 1.200000 Multiply/Divide –Use fewest number of sig figs Ex: 2.46 x.000003

5. Scientific Notation Remove insignificant zeroes Process: –Move decimal behind first non-zero –Write x 10 p p = places decimal was moved (- or +) Ex: 104,000,000.0000016

6. Units Numbers need units to be meaningful Use formulas to calculate units –d = m/v………m = dv……….v = m/d

7. Formulas Plug in for all but one variable and solve –Algebra! –Ex:

8. Converting Between Units Conversion factors represent how two units are related –1 dozen rolls 12 rolls

9. Conversions: Factor-Label Method Write known number (with unit) as a fraction –244 rolls 1 Write conversion factor (desired unit on top) –1 dozen rolls 12 rolls Do the math –244 rollsx1 dozen rolls 1 12 rolls

10. WRAP UP Convert 5.3 nm to km using the factor- label method. How many significant figures are there in the number.0007020?

11. WARM UP Calculate the density of a wood block with a volume of 9.27 cm 3 and a mass of 22.589 g.

12. WRAP UP Convert 106,500,000 to scientific notation. Convert 4.51 x 10 -4 to decimal notation.

13. WARM UP “Live to make the world less difficult for each other.” – George Eliot 1)How can you apply this to your own life? 2)Do you agree with this philosophy? Why?