The Metric System
-->Started about 300 years ago in France
-->Le Systeme International d'Unites *S1 system
-->7 Fundamental units (used for basic measurements)
*meter(m)-length
*kilogram(kg)-mass
*second(s)-time
*ampere(A)-current
*mole(mol)-amount
*kelvin(k)-temperature
*candela(cd)-Luminous Intensity
Length
-->standard unit is the metre
Mass
-->standard unit is the kilogram
Time
-->standard unit is the second
-->9, 192, 631, 770 vibrations of a cesium atom
Prefixes used with S1 Units
*we can put a prefix in front of the unit & change the power of it
*GEGA=Billion
*MEGA=Million
*kilo=thousand
*micro=millionth
*nano=small (billionth 10 to -9)
*pico=ten to the -12
Fundamental Unit 1m
deci(d) 10-1 10dm
centi(c) 10-2 100cm
milli(m)10-3 1000mm
micro(M) 10-6 1 000 000Mm
nano(n) 10-9 1 000 000 000nm
pico(p) 10-12 1 000 000 000 000pm
femto(fm) 10-15 1 000 000 000 000 000fm
254,000,000,000=2.54x10(11)
254 Gm
0.00000411 =4.11x10-6
4.11um
*DON'T use scientific notaion & prefixes together!!
Becomes very confusing
Experimental Accuracy
--> The max accuracy of any measurement is 1/2 of the smallest division of the measuring device
--> A ruler with measurements of millimeters has a max accuracy of +or- 0.5mm
ex. 20.6cm +or- o.05cm (1/2)
mm^ <-------------^
Meniscus --> curved top of liquid in a graduated cylinder
Significant zeros: *zero is the place keeper it is generally not significant.
*if a decimal is placed to the right of a zero it IS significant
*no zeros= all digits are important
Adding or Subtracting: Round to the LEAST precise number
1) 7.4212 - 3.54= 3.8812= 3.88
2)12.31 + 10.771= 23.071=23.1
Multiply or Divide: Round to the number with the FEWEST S.D.s
1)2.5 x 5.55 = 13.875-14
2)1.33421 x 19.531= 26.05845= 26.058
