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Learn about SI units, prefixes, and density calculations in this comprehensive guide. Understand base units, prefixes (kilo, mega, deci, centi, milli, micro, nano, pico), and how to calculate density. Dive into problem-solving steps with examples involving mass, volume, and density.
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CH. 2 - MEASUREMENT II. Units of Measurement (p. 33 - 39) C. Johannesson
A. Number vs. Quantity • Quantity - number + unit C. Johannesson UNITS MATTER!!
B. SI Units Quantity Symbol Base Unit Abbrev. Length l meter m Mass m kilogram kg Time t second s Temp T kelvin K Amount n mole mol C. Johannesson
kilo- mega- M k 103 106 deci- BASE UNIT d meter(m) Liter (L) gram (g) 100 10-1 centi- c 10-2 milli- m 10-3 micro- 10-6 nano- n 10-9 pico- p 10-12 B. SI Units Prefix Symbol Factor C. Johannesson
M V D = C. Derived Units • Combination of base units. • Volume (m3 or cm3) • length length length 1 cm3 = 1 mL 1 dm3 = 1 L • Density (kg/m3 or g/cm3) • mass per volume C. Johannesson
D. Density Mass (g) Volume (cm3) C. Johannesson
Problem-Solving Steps 1. Analyze 2. Plan 3. Compute 4. Evaluate C. Johannesson
D. Density • An liquid has a volume of 25 ml and a density of 13.6 g/ml. Find its mass. GIVEN: V = 25 ml D = 13.6 g/ml M = ? WORK: M = DV M = (13.6 g/ml)(25ml) M = 340 g C. Johannesson
WORK: V = M D V = 25 g 7.9 g/cm3 D. Density • Steel has a density of 7.9 g/cm3. What volume is occupied by 25 g of the metal? GIVEN: D = 7.9 g/cm3 V = ? M = 25 g V = 3.16 cm3 C. Johannesson
WORK: D = M V D = 30 g 3.37 cm3 D. Density • Copper has a mass of 30 g. What is the density of copper if the volume is 3.37 cm3 GIVEN: D = ? V = 3.37 cm3 M = 30 g D = 8.9 g/cm3 C. Johannesson