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PhySci1. KTM Temperature Density % Submerged. BURN SUGAR (ring-stand) OR MELT CHOCOLATE. Ask students why they smell what they do?. Kinetic Theory of Matter. All matter is made up of atoms and molecules that act like tiny particles. These tiny particles are always in motion.
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PhySci1 KTM Temperature Density % Submerged
BURN SUGAR (ring-stand) OR MELT CHOCOLATE Ask students why they smell what they do?
Kinetic Theory of Matter • All matter is made up of atoms and molecules that act like tiny particles. These tiny particles are always in motion.
Measurements indicate that the average speed of oxygen molecules in 20°C air is an amazing 1700km/h. At this speed, the odor from a hot cheese pizza in Washington, D.C., should reach Mexico city in about 115 minutes. • Why don’t we smell food from Mexico?
Bulb Thermometer Temperature How hot or cold something is (Colloquial definition) The average speed (kinetic energy) of the particles in a substance. (Scientific) ↑ Speed = ↑ Temperature ↓ Speed = ↓ Temperature
Hot Water Cold Water What Happens if I add a drop of food coloring to a glass of hot and cold water?
Erlenmeyer Flask Balloon What Happens if I put a balloon over an Erlenmeyer Flask and put it on a hot plate/burner? Why?
Density • Density is the amount of matter contained in an object in a given volume. • Density = mass of object / volume of object Mass: grams Volume: cm3 Density: g/cm3
Volume – irregularly shaped Water Displacement
A Graduated Cylinder Measures Volume 1cm3 = 1ml
Which one has a higher density? • The brick and the sponge have a similar volume meaning they take up roughly the same amount of space but the brick will be much heavier than the sponge. • Since the brick has more mass it has a higher density.
Density of Common Objects • Water = 1g/cm3 • Gold = 19.3g/cm3 • Concrete = 2.7g/cm3 • Iron = 7.8g/cm3 • Ice = 0.92g/cm3 • Air =0.001225 g/cm3 • If an object is denser than water (or another liquid) it will sink. • If an object is less dense than water (or another liquid) it will float.
Density Problems • If a 10.0cm3 blockof ice has a mass of 9.17g, what is the density of ice? • A piece of tin has a mass of 16.52g and a volume of 2.26cm3. What is the density of tin? • A piece of metal has a density of 11.3 g/cm3 and a volume of 6.7 cm3. What is the mass of this piece of metal? • A cube 6cm by 5cm by 3cm has a mass of 450g. Calculate its density.
Handoutsx3 • Density Lab • Density Column Worksheet • Density problems. • Water ml g cm3 experiment
Salt Water vs Fresh Water • Egg Demo: • Which one is denser? • Which one is it easier to swim in?
Density Question • If I have a wooden block that has a mass of 20g and a volume of 26cm3. What is its density? What happens to the density of that block of wood if you cut it in half?
WOOD BLOCK Mass = 20g Volume 26cm3 TWO WOOD BLOCKS Mass = 10g Volume 13cm3 Mass = 10g Volume 13cm3 WOOD BLOCK WOOD BLOCK WOOD BLOCK Cut in half Density = 0.77g/cm3 Density = 0.77g/cm3 Density = 0.77g/cm3 WOOD BLOCK What Happens if I cut one of the small wooden blocks in half again? Mass = ??? Volume = ??? Density = ??? WOOD BLOCK
Density does NOT depend on the amount of the substance you have. • Regardless of whether you have a small piece of gold or a giant truck full of it, the density of gold will be 19.3g/cm3
Volume Displacement It is important to remember that for h20 1g = 1ml = 1cm3 1000kg = 1000L = 1m3 H20 = 1g/cm3 or 1000kg/m3
Iceberg!!!! • What percentage of an iceberg is hidden beneath the water? • Density of water is 1g/cm3 • Density of Ice is 0.92g/cm3 • So 0.92g/cm3/ 1g/cm3 = 0.92 x100 = 92%
Knock on Wood • A branch from a tree extending out over a river snaps and falls into the water. If it has an overall density of 0.7g/cm3, will it sink or float and if it floats how much of it will be visible?
Knock on Wood • A branch from a tree extending out over a river snaps and falls into the water. If it has an overall density of 0.7g/cm3, will it sink or float and if it floats how much of it will be visible?
Floating Basketball • A basketball has a mass = 624g and a volume of 7512.1cm3. What percentage of a basketball will float above water?
Floating Basketball • A basketball has a mass = 624g and a volume of 7512.1cm3. What percentage of a basketball will float above water?
A basketball has a mass = 624g and a volume of 7512.1cm3. What percentage of a basketball will float above water? • D = m/v = 624g/ 7512.1cm3 = 0.831g/cm3 • Dball / Dwater = 0.831g/cm3 / 1g/cm3 x 100 = 8.3% • 91.7% of a basketball will float above water.
Rank each Objects Density from the Most Dense to the Least Dense