Measurement I. Units of Measurement Number vs. Quantity SI Base Units & Prefixes Conversions Derived Units Density Calculations

Number vs. Quantity Quantity - number + unit UNITS MATTER!!

SI Units Quantity Base Unit Symbol Length meter m Mass kilogram kg Time second s Temp kelvin K Current ampere A

SI Units Prefix Symbol Factor mega- M 106 kilo- k 103 deci- d 10-1 centi- c 10-2 milli- m 10-3 micro-  10-6 nano- n 10-9 pico- p 10-12

SI Prefix Conversions To the left or right? 1. Find the difference between the exponents of the two prefixes. 2. Move the decimal that many places. To the left or right?

UNIT NUMBER UNIT SI Prefix Conversions = 0.532 532 m = _______ km

SI Prefix Conversions Prefix Symbol Factor mega- M 106 kilo- k 103 deci- d 10-1 centi- c 10-2 move left move right milli- m 10-3 micro-  10-6 nano- n 10-9 pico- p 10-12

SI Prefix Conversions 0.2 32 45,000 0.0805 1) 20 cm = ______________ m 2) 0.032 A = ______________ mA 3) 45 m = ______________ nm 4) 805 dm = ______________ km 32 45,000 0.0805

D M V D = M V Derived Units Combination of base units. Volume - length  length  length 1 cm3 = 1 mL 1 dm3 = 1 L Density - mass per unit volume (g/cm3) D M V D = M V

D M V Density V = 825 cm3 M = DV D = 13.6 g/cm3 An object has a volume of 825 cm3 and a density of 13.6 g/cm3. Find its mass. GIVEN: V = 825 cm3 D = 13.6 g/cm3 M = ? WORK: M = DV M = (13.6 g/cm3)(825cm3) M = 11,220 g D M V

D M V Density D = 0.87 g/mL V = M V = ? M = 25 g V = 25 g 0.87 g/mL 1) A liquid has a density of 0.87 g/mL. What volume is occupied by 25 g of the liquid? GIVEN: D = 0.87 g/mL V = ? M = 25 g WORK: V = M D D M V V = 25 g 0.87 g/mL V = 28.7 mL

D M V Density M = 620 g D = M V = 753 cm3 D = ? D = 620 g 753 cm3 2) You have a sample with a mass of 620 g & a volume of 753 cm3. Find density. GIVEN: M = 620 g V = 753 cm3 D = ? WORK: D = M V D M V D = 620 g 753 cm3 D = 0.82 g/cm3