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Some, but not all physical changes can be _______________. You could refreeze the water into ice, but you cannot put your hair back together if you don’t like your haircut!. Physical vs Chemical Properties:
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Some, but not all physical changes can be _______________.You could refreeze the water into ice, but you cannot put your hair back together if you don’t like your haircut!
Physical vs Chemical Properties: http://www.bing.com/videos/search?q=physical+vs.+chemical+properties&FORM=HDRSC3#view=detail&mid=D6BF2173877E62CD1986D6BF2173877E62CD1986 Obla Di Obla Da – The Properties Song http://www.youtube.com/watch?v=uJOGy0dgmUU http://www.teachertube.com/viewVideo.php?video_id=129193
Classify each statement as physical or chemical property/change. • Pure metals have a higher luster (are shiny and reflect light). • The surfaces of some metals become dull when exposed to air. • Nitrogen gas, a relatively nonreactive material at room temperature, can form nitrogen oxides at the high temperatures of an operating automobile engine. • Milk turns sour if left too long at room temperature. • Diamonds are hard enough to be used as a coating for drill bits. • Leavened bread dough increases in volume if it allowed to “rise” before baking. • Generally, metals are better conductors of heat and electricity than are nonmetals. • Unreactive argon gas, rather than air, is used to fill many light bulbs to prevent the metal filament wire inside the bulb from being destroyed through chemical reactions. • Metals are typically ductile (can be drawn into wires).
Real Life Problem: Designing the Penny • _____ of materials is an issue when manufacturing coins and paper money. • Early _________ copper became too expensive to be used as primary metal in pennies • Zinc replaced most of the copper in all post 1982 pennies PROs - Zinc – about as _______; almost as dense, readily available and less expensive than copper CONs – more ___________________________(zinc-plated steel pennies created in 1943 corroded and looked considerably different)
Solved the penny issue in early 1980s • ________________properties best fit for outside of the coin and ____________ properties best fit for inside of the coin (increase coin’s durability and maintain familiar appearance)
http://vital.cs.ohiou.edu/steamwebsite/downloads/ChangeLab.swfhttp://vital.cs.ohiou.edu/steamwebsite/downloads/ChangeLab.swf Online Quiz http://www.teachertube.com/viewVideo.php?video_id=214083
What is ___________? If you take the same volume of different substances, then they will weigh different amounts. Density is the ______________________ Wood Water Iron 1 cm3 1 cm3 1 cm3 IRON 0.50 g 1.00 g 8.00 g Q) Which has the greatest mass and therefore the most dense? http://www.youtube.com/watch?v=GMNpPgLT8Fk
Density Equation: g M = D x V V = M / D Mass Density = Volume mL (for liquids) or cm3 (for solids) g/mL or g/cm3 http://science360.gov/obj/video/f2511bad-b43f-4dbd-84f9-ace57941ac90/mass-volume-density NHL Hockey Rinks
DENSITY OF A _________________ SOLID • Find the _______ of the solid on a balance. • Measure the three lengths and calculate the _____________. (ie V = l x w x h ) • Calculate the Density. m = 240 g 2.0 cm Density= m = 240 =10.0 g/cm3 V 24 3.0 cm 4.0 cm
DENSITY OF AN _________________ SOLID 1. Find the _____ of the solid on a balance. 2. Fill the Measuring Cylinder with Water to a known Volume. 3. Add the Object. 4. Work out the Volume of Water that is ___________________ 5. Calculate the Density. m = 360 g 80 ml 50 ml Density = m = 360 =12.0 g/cm3 V 30
DENSITY OF AN _________________ SOLID 1. Find the ____ of the solid on a balance. 2. Add water until just overflowing. 3. Place a Measuring Cylinder under the spout. 4. Add the Object. 5. Collect the Water and read off the ______________ 6. Calculate Density • OR use a Eureka (overflow) Can to find the Volume. m = 440 g 40.0 ml Density = m = 440 =11.0 g/cm3 V 40
DENSITY OF A _____________ • Find the ______ of an empty graduated cylinder. 2. Add a certain ___________of Liquid. • Find the Mass of the Measuring Cylinder and Liquid 4. Calculate the Mass of Liquid. • How? • Mass of Liquid = Mass of Measuring Cylinder and Liquid – Mass of empty Measuring Cylinder • Calculate Density of Liquid. 25.0 g 25.0 g 45.0 g 20.0 ml 45 – 25 = 20 g Density = m = 20 =1.00 g/mL V 20
Density Practice Problems • What is the density of a piece of wood that has a mass of 25.0 grams and a volume of 29.4 cm3? 2. A piece of wood that measures 3.0cm by 6.0cm by 4.0 cm has a mass of 80.0 grams. What is the density of the wood? • Would the piece of wood in #2 float in water?
An ice cube measuring 5.80cm by 5.80cm by 5.80cm has a density of 0.917g/cm3. What is the mass? 5. The density of aluminum is 2.7g/ml. If the mass of a piece of aluminum is 244g, what is the volume of the aluminum?
How to TEST for GASSES! Oxygen (O2), Hydrogen (H2) & Carbon Dioxide (CO2) colorless and odorless (for the most part)…. SOOO how can you tell which gas is emitted after a chemical reaction????? http://www.youtube.com/watch?v=LiAvDpl5aJA