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CHEMISTRY SEPTEMBER 30, 2014. SI/ SIGNIFICANT FIGURES/SCIENTIFIC NOTATIONS. SCIENCE STARTER. Verbal Science Starter. OBJECTIVE. SWBAT Apply the SI units Apply the significant rules Apply the scientific notation rules. AGENDA. Science Starter SI units Significant Figures
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CHEMISTRYSEPTEMBER 30, 2014 SI/SIGNIFICANT FIGURES/SCIENTIFIC NOTATIONS
SCIENCE STARTER • Verbal Science Starter
OBJECTIVE • SWBAT • Apply the SI units • Apply the significant rules • Apply the scientific notation rules
AGENDA • Science Starter • SI units • Significant Figures • Scientific Notation
IMPORTANT DATES • Makeup Quiz on Wednesday during 4th period or 9th period (Up to 4:15PM) • Lab – Thursday • Quiz 03 – Friday • Test 01 – Next Friday
SEPARATION TECHNIQUES • Chromatography • Filtration • Evaporation • Distillation • Magnetism
CHROMATOGRAPHY • Definition: Method in which components of a mixture is separated based on how quickly different molecules dissolved in a mobile phase solvent move along a solid phase • One type is called Paper Chromatography • Usually used to identify chemicals (coloring agents) • Example: Identifying the chemicals in a marker
FILTRATION • Method for separating an insoluble solid from a liquid • Popularly used in water treatment • Example: Separating river water
EVAPORATION • Method used to separating a homogeneous (solution) mixture of a soluble solid and a solvent • Involves heating the solution until the solvent evaporates • Examples: Sugar water solution • Heat the solution until the water (solvent) dissolve leaving behind the sugar
DISTILLATION • Method used to separate a liquid from a solution • Similar to evaporation but the vapor is collected by condensation • Example: Sugar Water solution
MAGNETISM • Method used to separate two solids with one having magnetic properties • Example: Separating iron filings and dirt mixture
SEPARATING FUNNEL • Method for separating two immiscible liquids (liquids that do not dissolve well) • Example: Oil and water
Miscible vs. Immiscible • Miscible: Forming a homogeneous solution when added together • Immiscible: do not form a homogeneous solution when added together. Do not dissolve well
SI UNITS INTERNATIONAL SYSTEM OF UNITS
SI UNITS • standard system of measurements used in chemistry • enable scientists to communicate with one another • there are 7 base units • all other units are derived from these 7 base units
7 SI base units • ampere (A) – measures electric current • kilogram (kg) – measure mass • meter (m) – measure length • second (s) – measure time • kelvin (K) – measure thermodynamic temperature • mole (mol) – measure amount of substance • candela (cd) – measure luminous intensity
CONVERSION BETWEEN UNITS • Step 1: Draw the picket fence • Step 2: Identify the given • Step 3: Identify what you are looking for • Step 4: Identify the equivalent relationship • Step 5: Get rid of the units • Step 6: Do the math • Step 7: Check for the final unit(s)
EXAMPLE • 10 m = __________________cm • Step 1: Draw the picket fence
EXAMPLE – CONT’ • Step 2: Identify the given • 10 m • Step 3: Identify what you are looking for • cm • Step 4: Identify the equivalent relationship • 1cm = 0.01 m
EXAMPLE – CONT’ • Step 5: Set up the problem
EXAMPLE – CONT’ • Step 6: Get rid of the units
EXAMPLE – CONT’ • Step 7: Do the math • Step 8: Check for the final unit(s)
DEFINITION • a prescribed decimal place that determines the amount of rounding off to be done based on the precision of the measurement • consist of all digits known with certainty and one uncertain digit.
RULES FOR DETERMINING SIGNIFICANT FIGURES • nonzero digits are always significant • example: 46.3 m has 3 significant figures • example: 6.295 g has 4 significant figures
RULE – CONT’ • Zeros between nonzero digits are significant • example: 40.7 m has 3 significant figures • example: 87,009 m has 5 significant figures
RULE – CONT’ • Zeroes in front of nonzero digit are not significant • example: 0.009587 m has 4 significant figures • example: 0.0009 g has 1 significant figure
RULE – CONT’ • Zeroes both at the end of a number and to the right of a decimal point are significant • example: 85.00 g has 4 significant figures • example: 9.0700 has 5 significant figures
EXAMPLE • 1. Give the number of significant figures in each of the following. • a) 10.0005 g ______ • Do the next 3 problems
EXAMPLES - answers • b) 0.003423 mm __4____ • c) 67.89 ft___4___ • d) 78.340 L __5____
MULTIPLICATION/DIVISION RULES • The number of significant figure for the answer can not have more significant figures than the measurement with the smallest significant figures
EXAMPLES 12.257 x 1.162 = 14.2426234 • 12.257 = 5 significant figures • 1.162 = 4 significant figures • Answer = 14.24 (4 significant figures)
EXAMPLE - Answer • 12.257 = 5 significant figures • 1.162 = 4 significant figures
EXAMPLE – Answer cont’ • Answer = 14.24 (4 significant figures)
ADDITION/SUBSTRATION RULES • The number of significant figure for the answer can not have more significant number to the right of the decimal point