Chapter 1 Metric Units PS 12:1 PS 12:2

 If I tell you that I have 11, what do you know?  For a measurement to make sense, it requires both a # and a unit.  EX: I have 11 brothers/sisters.  You should always express measurements in # ’ s and a unit so that their meaning is clear. Many units that you are familiar with are not units used in science( feet, inches, Fahrenheit) SI Units of Measurement

SI Continued  Scientists use a set of measuring units called SI, or the International System of Units  This is a revised version of the metric system.  By everyone using the SAME system of units, scientists can easily interpret one another ’ s measurements.

7 Base Units  The seven are listed on page 16  Length – meter (m)  Mass – gram (g)  Volume – Cubic meter (m 3 ) = Liter(L)  Length: straight-line distance between 2 points  Mass: quantity of matter in an object/sample  Volume: amount of space taken up by an object

 Density = Mass = Kg Volume m 3 Now let ’ s practice a little with converting within SI kids hate dances because dj ’ s cruddy music k,h,da,base,d,c,m Kilo., hecta, deca., base, deci., cent., milli. Density – kg/m 3 Density: the ratio of an object ’ s mass to its volume

 EX: 5kg = _____ g  5.0kg = ______g  Move the decimal 3 spaces to the right to get to the base unit gram  K,ha,da,base(gram is the base unit)  Answer:  5kg = 5000g  Use this ex and complete the worksheet Worksheet practice

Metric Conversions Ladder Method T. Trimpe

KILO 1000 Units HECTO 100 Units DEKA 10 Units DECI 0.1 Unit CENTI 0.01 Unit MILLI Unit Meters Liters Grams Ladder Method How do you use the “ ladder ” method? 1 st – Determine your starting point. 2 nd – Count the “ jumps ” to your ending point. 3 rd – Move the decimal the same number of jumps in the same direction. 4 km = _________ m How many jumps does it take? Starting Point Ending Point 4. 1 __. 2 3 = 4000 m

Try these conversions using the ladder method mg = _______ g 1 L = _______ mL160 cm = _______ mm 14 km = _______ m109 g = _______ kg 250 m = _______ km Conversion Practice Compare using, or =. 56 cm 6 m 7 g 698 mg

Write the correct abbreviation for each metric unit. 1) Kilogram _____ 4) Milliliter _____ 7) Kilometer _____ 2) Meter _____ 5) Millimeter _____ 8) Centimeter _____ 3) Gram _____ 6) Liter _____ 9) Milligram _____ Try these conversions, using the ladder method. 10) 2000 mg = _______ g 15) 5 L = _______ mL 20) 16 cm = _______ mm 11) 104 km = _______ m 16) 198 g = _______ kg 21) 2500 m = _______ km 12) 480 cm = _____ m 17) 75 mL = _____ L 22) 65 g = _____ mg 13) 5.6 kg = _____ g 18) 50 cm = _____ m 23) 6.3 cm = _____ mm 14) 8 mm = _____ cm 19) 5.6 m = _____ cm 24) 120 mg = _____ g Metric Conversion Challenge

Compare using, or =. 25) 63 cm 6 m 27) 5 g 508 mg 29) 1,500 mL 1.5 L 26) 536 cm 53.6 dm 28) 43 mg 5 g 30) 3.6 m 36 cm

 -indicates how many times a unit should be multiplied or divided by ten  Figure 15 on page 17 shows some common metric prefixes  EX 9ms = 9 s = 0.009s 1000 *Note – dividing by 1000 same as multiplying by Metric Prefixes

-- can make a unit larger EE X 12 km = 12 x 1,000m = 12,000 m CC onversion Factors – a ratio of equivalent measurements that is used to convert a quantity expressed in one unit to another unit. LL et ’ s look together on page 18 of you text to work through an example of this FACTOR LABEL Method More on metric prefixes

 Thermometer – thermo(heat)meter(measure) An instrument that measures temperature, or how hot an object is. Let ’ s look at page 21 together Fahrenheit and Celsius and kelvin conversions Copy the formulas found on page 20 into your notes Measuring Temperature

 K = 0 C formula  Convert 205 K = ______ 0 C 205k – 273 = C 42 0 C = ___ K 42 0 C = 315K Practice converting temp.

 0 C = (F – 32) x 5/9 AND F = 0 C x 9/  Copy the example from the bottom of Page 878 in your text into your notes  Do the following conversions on your own for practice using the example you just copied  F = _____ 0 C  14F = _____ 0 C More practice

 65C = _____F  22C = _____F One more set of practice in F

 Length Temperature  Mass Volume  Time Electric Current  Second (s) Ampere (a)  Kelvin (k) Meter (m)  Liter (l) Kilogram (kg) What unit to use when?

Presenting Sci. Data  Organizing Data – Scientists organize data using tables and graphs.  These make it easier to spot patterns/trends to support of disprove their hypothesis Data Tables- the simplest way to organize data

Organizing data  Line Graphs – Useful for showing changes that occur in related variables  Manipulated variable – x-axis  Responding variable – y-axis Slope = Rise Run

Direct proportion –As one goes up/down the other goes up/down the same amount Inverse proportion – As one goes up/down the other goes down/up Thumb demonstration Look at fig. 22 Do Data Analysis page 24

More organizing data BB ar Graphs- often used to compare a set of measurements, amounts, or changes. CC ircle Graphs- a divided circle that shows how the part or share of something relates to the whole.