Ch. 2 Sec. 1

Measures in ScienceCh. 2 Sec. 1Metric System & SI UnitsFrench Scientists adopted metric system in 1795Metric system uses powers of 1010 millimeter = 1 centimeter10 centimeter = 1 decimeter10 decimeter = 1 meterThere are 7 base unitsBase units ChartSI Base UnitsBase QuantityBase UnitSymbolLengthMeterm MassKilogramkgTimeSecondsTemperatureKelvinKAmount of SubstanceMolemolElectric CurrentAmpereALuminous IntensityCandelacdDerived unitsCombination of the base unitsSpeed or velocity = meters per second, m/sEnergy = joule, kg m2/s2

SI Unit PrefixesPrefixSymbolMultiplierSci. NotationPicop1/1,000,000,000,00010-12Nanon1/1,000,000,00010-9Micro1/1,000,00010-6Millim1/1,00010-3Centic1/10010-2Decid1/1010-1Kilok1000103MegaM1,000,000106GigaG1,000,000,000109TeraT1,000,000,000,0001012Scientific NotationAble to make using really large or small numbers easierExpressing decimal numbers in powers of 10N x 10nMove decimal point until only one non-zero digit remainsCount the number of spaces and use that as exponentEarth to Mars = 227 800 000 000m2.278 x 1011mMass of electron = 0.000 000 000 000 000 000 000 000 000 000 911 kg9.11 x 10-31kgExpress in Sci. Notation5800 450 000302 000 00086 000 000 0000.000 5080.000 000 450.00036000.004Express in Sci. Notation5800 = 5.8 x 103450 000 = 4.5 x 105302 000 000 = 3.02 x 10886 000 000 000 = 8.6 x 10100.000 508 = 5.08 x 10-40.000 000 45 = 4.5 x 10-70.0003600 = 3.600 x 10-40.004 = 4 x 10-3Converting UnitsWhat is the equivalent in km of 670 m?1 km = 1000 m(1000 m)/ (1 km) = 1Using a Conversion Factor you can determine the relationship between two unitsMultiplier equal to one670 m = (670 m) (1 km / 1000 m)(670 m x 1 km) / 1000 m = 0.670 kmLabel units will cancel outConverting Units Practice1.1 cm meters76.2 pm millimeters2.1 km meters2.278 x 1011 m kilometers147 g kilograms11 Mg kilograms7.23 g kilograms478 mg kilogramsConverting Units Practice1.1 cm 1.1 x 10-2 m76.2 pm 7.62 x 10-8 mm2.1 km 2.1 x 103 m2.278 x 1011 m 2.278 x 108 km147 g 1.47 x 10-1 kg11 Mg 1.1 x 104 kg7.23 g 7.23 x 10-9 kg478 mg 4.78 x 10-4 kgAdding and Subtracting in Sci. NotationWhen adding or subtracting, make sure the powers of 10 are the same (10N)4 x 108 + 3 x 108(4 + 3) x 1087 x 108(4.1 x 10-6) (3.0 x 10-7)(4.1 x 10-6) (0.30 x 10-6)(4.1 0.30) x 10-63.8 x 10-6Multiplying & Dividing in Sci. NotationMultiply or divide the values and the unitsAdd (if multiplying) or subtract (if dividing) the exponents(4 x 103 kg)(5 x 1011 m)(4 x 5) x 103 + 11 kgm20 x 1014 kg m 2 x 1015 kg m(8 x 106 m3) / (2 x 10-3 m2)(8/2) x 106 (-3) m(3-2)4 x 109 mIf units have powers, add or subtract accordingly