SI Base Units, Metric System, Factor Label Method ConversionsSI Base Units, Metric System, Factor Label Method Conversions

ObjectivesObjectives 1.Define SI Base Units for Mass, Length, Time, Temperature, Amount of a substance, Electric Current, and Luminous Intensity 2.Explain how adding a prefix changes a unit. 3.Perform Density and Temperature Calculations. 4.Perform Unit Conversions using Factor Label Method. 5.Convert data from standard form to scientific notation and from scientific notation to standard form. 6.Use various measuring devices to determine precision and accuracy.

Vocabulary TermsVocabulary Terms 1.Quantitative Data 2.Qualitative Data 3.Hypothesis 4.Base Unit 5.Kilogram 6.Meter 7.Liter 8.Second 9.Kelvin 10.Mole 11.Ampere 12.Candela 13.Density 14.Volume 15.Absolute Zero 16.Scientific Notation 17.Precision 18.Accuracy 19.Metric Ruler 20.Graduated Cylinder 21.Meniscus 22.Triple Beam Balance

Scientific Law, Theory, & HypothesisScientific Law, Theory, & Hypothesis Scientific Law – A rule or principle describing a physical relationship or event that is observed and experimented, and NEVER changes. Scientific Theory – A set of widely accepted explanations of observations and phenomena, CAN change if there is consistent evidence. Scientific Hypothesis – A tentative explanation for an observation or phenomenon, used to make predictions.

Qualitative vs. Quantitative DataQualitative vs. Quantitative Data Qualitative Data: Observations made by scientists that describes the information using the five senses – sight, smell, taste, sound, touch. Examples: Mr. A is wearing a green shirt, Mr. A has a loud voice, A Lemon has a sour taste, Tape feels sticky, etc. Quantitative Data: Observations made by scientists that describes the numerical value of information. Examples: Mr. A is 6’1” tall, Mr. A has 10 fingers and toes, The classroom is 78 degrees Fahrenheit, You got 9 out 10 correct on the Lab Safety Test, etc.

When you do something with an observation, like draw a conclusion, offer an explanation or decide that a chemical reaction occurred, then you are making an inference. An observation is the awareness of some condition; inference is the result of a mental process which attempts to explain or catalog or speculate about that observation.

Significance: Precision vs. AccuracySignificance: Precision vs. Accuracy The Significance of a measurement is determined by the precision and accuracy of the device being used. Accuracy – Refers to how close a measured value is to an accepted value. Correctness Precision – Refers to how close a series of measurements are to one another. Consistency From the following data table determine the precision and accuracy for students A, B, and C. The following are test results based on 100%. Student AStudent BStudent C Trial 172%93%95% Trial 270%66%97% Trial 371%77%98% Average71%78.66%96.66% Precise NeitherBoth

SI Base UnitsSI Base Units QuantityBase Unit MassKilogram (kg) LengthMeter (m) TimeSecond (s) TemperatureKelvin (K) Amount of a substanceMole (mol) Electric CurrentAmpere (A) Luminous IntensityCandela (cd) Base Unit: A defined unit in a system of measurement based on an object or event in the physical world.

Prefixes Used with SI UnitsPrefixes Used with SI Units PrefixSymbolFactor Scientific Notation Example GigaG Gigameter (Gm) MegaM Megagram (Mg) Kilok Kilometer (km) Hectoh Hectoliter (hL) Decada Decagram (dag) Decid 1/ Deciliter (dL) Centic 1/ Centimeter (cm) Millim 1/ Milligram (mg) Microµ 1/ Microgram (µg) Nanon 1/ Nanometer (nm)

Metric Conversions Using Factor-Label MethodMetric Conversions Using Factor-Label Method 1 Dozen eggs = 12 eggs12 inches = 1 foot 60 seconds = 1 minute16 ounces = 1 pound Factor Label Method: A way to convert a ratio of equivalent values to express the same quantity in different units. Examples: 24 inches = ____?____ feet = 2 feet Given Units Units to Cancel Units to Get to Equivalent Ratio 24 inches 12 inches 1 feet

180 seconds = _____?______ minutes = 3 minutes 4800 grams = _____?______ kilograms 4800 grams 1 kilogram 1000 grams = 4.8 kilograms 12 meters = _____?______ decimeters 12 meters 10 decimeters 1 meter = 120 decimeters Factor Label PracticeFactor Label Practice 180 seconds 60 seconds 1 minute

2 Step Factor Label Method2 Step Factor Label Method 7200 seconds = _____?______ hours 7200 seconds 1 minute 1 hour 60 seconds 60 minutes = 2 hours 5500 centimeters = _____?______ kilometers 5500 centimeters 1 meter 1 kilometers 100 centimeters 1000 meters =.055 kilometers micrograms = _____?______ kilograms micrograms 1 gram 1 kilograms micrograms 1000 grams = kg

Derived Units: DensityDerived Units: Density Volume: the amount of space occupied by an object. Can measured in Liters, milliliters, ounces, quarts, pints, gallons, and cubic centimeters (cm 3 ). Volume = length x width x height Density: the mass per unit volume of a given material. Equation: Density = Mass / Volume Examples – Water has a density of 1.0 g/mL Ice has a density of 0.92 g/mL Aluminum has density of 2.7 g/mL What has a greater density oil or water? What has a greater density, a brick or a pillow?

Temperature ConversionsTemperature Conversions Hot and Cold are qualitative descriptions of temperature. Using the three different temperature scales describes a quantitative observation. The three temperature scales include; Celsius, Fahrenheit, and Kelvin 1.°C = (°F – 32) / °F = 1.8(°C) K = °C Known Values for Water Freezing Point of Water = 0 °C, 32 °F, 273K Boiling Point of Water = 100 °C, 212 °F, 373K Absolute Zero – The temperature at which a substance would have zero kinetic energy, particles are not moving at all. (0 K, -273 °C, °F) Do the following Temperature Conversions: a. 44 °C = _______ °F b. 104 °F = _______ °C c. 125 °C = ______K

Scientific NotationScientific Notation General Formula: M x 10 n M = a number between 1-10 but cannot be 10 ( ) n = the number of decimal places moved Scientific Notation: expresses numbers as a multiple of two factors; a number between 1 and 10 (M); and 10 raised to a power, or exponent (n) Examples: 1,000 = 1.0 x ,000 = 1.5 x = 4.98 x ,542,327 = x = 5.0 x = x = 6.52 x = 1 so 4.1 x 10 0 = 4.1