Scientific units
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This document discusses scientific units of measurement. It covers the metric system/SI system which is the international standard for measurement. The SI system is based on seven base units: meter, kilogram, second, Kelvin, mole, ampere, and candela. It also defines common metric prefixes like milli and kilo. Derived units are units like volume which are calculated from base units. Mass is distinct from weight, as weight depends on gravity. The document provides examples of unit conversions for length, volume, and mass within and between metric and US customary systems.
Scientific units
- 1. SCIENTIFIC UNITS OF THE MEASURING SYSTEM
- 2. Measurements Components of a Measurement •Numerical quantity •Unit •Name of substance Numerical quantity 325.0 mL water Name of the substanceunit
- 3. Metric System • Also called the International or SI system. • Based on # 10. • SI states base Units. • Other units derived from base units. • Prefixes indicate power of ten.
- 4. SI BASE UNITS Magnitude Name Symbol • Length meter m • Mass kilogram kg • Time second s • Temperature Kelvin K • Amount mole mol • Current ampere A • Luminous candela cd
- 5. Common Metric Prefixes Prefix Symbol Decimal Exponential Mega M 1 000 000 106 kilo k 1000 103 centi c 0.01 10-2 milli m 0.001 10-3 micro µ 0.000 001 10-6
- 6. Derived Units Volume = side x side x side Volume = m3 or Liter Density = mass/volume Density = kg/m3
- 7. MASS is the amount of matter in an object. MASS = WEIGHT? 90 kg 90 kg Earth Moon w = 882 N w= 147 N w = m g Weight is force
- 8. Prentice-Hall ©2002 Burns 4/e Chapter 3 Slide 8 of 59 Mass Units • Important Equivalences for mass messures: • 1 kg = 1000g 1 g = 0.001 kg • 1 mg = 0.001 g 1 g = 1000 mg • 1 μg = 0.001 mg = 0.000001 g • 1 g = 1,000,000 µg
- 9. Prentice-Hall ©2002 Burns 4/e Chapter 3 Slide 9 of 59 Insert figure 3.10 Equivalent Mass
- 10. Prentice-Hall ©2002 Burns 4/e Chapter 3 Slide 10 of 59 Volume Equivalneces • 1 m3 = (100 cm)3 = (100)3 cm3 = • 1,000,000 cm3 • 1 cm3 = 1 cc = 1 mL (milliliter) • 1mL = 0.001 L y 1000mL = 1 L (liter) • 1 L = 1 dm3 = 0.001 m3 • 1mL = 1000 µL (microliter, a million de liters)
- 11. Prentice-Hall ©2002 Burns 4/e Chapter 3 Slide 11 of 59 Insert figure 3.5 Relation between measures of volume and length
- 12. Prentice-Hall ©2002 Burns 4/e Chapter 3 Slide 12 of 59 Insert figure 3.13 Measure a volume lecture Observe the concave edge
- 13. Derived Units Using the information found in the web page: http://www1.bipm.org/en/si/ Answer the following questions: a)Why is it name SI? b)when the world’s adopt the SI? c)What is the Importance of SI? d)Make a table of base units definition. e) Make a table of derived units. ACT #4
- 14. SCIENTIFIC UNITS OF THE MEASURING SYSTEM
- 16. Prentice-Hall ©2002 Burns 4/e Chapter 3 Slide 16 of 59 Insert Fig. 3.4 Length Units
- 17. UNIT SYSTEMS’ : * SI: Metric System (m/k/s) * USCS: U.S. Customary System Unit (f/p/s) Measurements
- 18. Measurements What does TO MEASURE mean? To compare a magnitude with other of the same kind. * Measurements are expressed in unit values Measurements
- 19. a)15 ft to m b)35 m to ft c)300 m/s to km/h d)80 ft/s to km/h e)5 m2 to cm2 Convert: 1 m = 3.28 ft 1 kg = 2.20 lb 1 in.= 2.54 cm 1 mi.= 1 609 m 1 gal. = 3.785 L 1 yd = 3 ft 1 L = 1 000 cm3 1 dm = 10 cm 1 oz. =30.56 mL
- 20. Now… Join in pairs and answer the class activity. Convert: 1 m = 3.28 ft 1 kg = 2.20 lb 1 in.= 2.54 cm 1 mi.= 1 609 m 1 gal. = 3.785 L 1 yd = 3 ft 1 L = 1 000 cm3 1 dm = 10 cm 1 oz. =30.56 mL
- 21. # . # # x 10(+ / - power) SCIENTIFIC NOTATION
- 22. a) 1 080 000 m b) 0.000 005 s c) 53 760 000 g d) 0.000 047 42 s e) 0.008 524 9 m Use Scientific Notation and prefixes to express the following magnitudes: ACT #2
- 23. Bibliography • Fundaments of Chemistry Ralph A. Burns Prentice Hall