Measurement and the Metric System Quantitative observations

Fundamental quantities Measurement Fundamental quantities Direct measurement Indirect measurement Derived quantities Calculations Density Heat energy

Rules for Significant Measurements One place past the smallest calibration Indicates where uncertainty is Communicate precision of the instrument

Protocols for deriving quantities Multiplication and division Addition and subtraction Rounding values

Metric System Developed in France in 1795 Revised and called International System of Measurements (SI) in 1960 Based on units of 10

SI Base Units Quantity SI base unit symbol Length Meter m Mass gram g Temperature Kelvin Celsius K oC Time Second s Liquid volume Liter L Amount of substance Mole mol

Memorize these !!!!! * “unit” refers to “base unit” 1 Kilo = 1 x 103 units 1 Hecto = 1 x 102 units 1 Deka = 1 x 101 units Basic unit = 1 1 x 101 deci (d) = 1 unit 1 x 102 centi (c)= 1 unit 1 x 103 milli(m) = 1 unit 1Giga(G) = 1 x 109 units 1Mega(M) = 1 x 106units 1 x 106 Micro(µ) = 1 unit 1 x 109 Nano(n) = 1 unit 1 x 1012 Pico(p) = 1 unit

Conversions Practice

Density Density is calculated by: D = mass volume Amount of matter per unit volume Water: 1.000 g/ ml at 25C Iron: 7.87 g/cm3 Lead 11.3 g/cm3 Density is calculated by: D = mass volume

Density Density is the amount of matter in a given space (volume) D = mass volume

Density Measuring liquid volume Volume displacement

Density Measuring solid volume Cylinder = V =πr2h Cube = length x width x height Cylinder = V =πr2h

Density Ex: A solid displaces 45.67 ml of water and has a mass of 98.5 grams. Calculate its density. Is it a block of lead?

Density practice

Specific gravity Comparison of the ratio of the density of a substance to the density of liquid water at 4C (1.00g/ml)

Temperature Scales Temperature is the measure of the average kinetic energy of a system. Implies molecular motion Celsius temperature Kelvin temperature

Temperature Scales Fahrenheit Celsius Kelvin Water Boils 373 K 212oF 100oC Water Freezes 32oF 0oC 273 K Molecular Motion Stops -460oF -273oC 0 K (absolute zero)

Converting between Temperature Scales Fahrenheit and Celsius: oC = 5/9 (oF-32) oF = (9/5 x oC)+32 Ex.What is the Celsius value for 60.0oF? oC = 5/9(60-32) oC = 5/9(28) oC = 15.55 oC =15.6

K = oC + 273 From Celsius to Kelvin: K = 80 + 273 K = 353 Ex.80.0oC would be what value on the Kelvin scale? K = 80 + 273 K = 353

Heat and Specific Heat Heat is the flow of thermal energy in a system Heat flows from hotter to cooler Ice cubes! Heat can flow into or out of a system

Heat and Specific Heat Heat transfer that causes temperature changes simply change in KINETIC ENERGY Heat transfer that causes phase changes imply change in POTENTIAL ENERGY

The Joule Metric unit of energy 4.18 joules raises 1.00g of water 1C. This is the SPECIFIC HEAT OF WATER!

Percent Composition

When you see %, think…… Part X 100 = % Whole

Percent Composition percent by mass % composition = Mass of element x 100% mass of compound

Terms to review Fundamental and derived quantities Precision and accuracy Matter Mass Volume Density Significant Figures % composition Scientific notation Metric system Dimensional analysis