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Topic: Measurement Aim: Describe density and how it is measured. Do Now: 1. Copy the topic, aim and homework 2. Take out the blue Mass Sheet from yesterday. 3. Tape the Density ISA into ISA section. HW: Temperature Reading Let’s review… 1. Describe volume. (Remember the key word!!!) 2. Describe mass. (Remember the key word!!!) 3. Identify the instrument used to measure. 4. Identify the instrument used to measure mass. 5. Identify the units used to measure mass. Mass = 290.2g Mass = 536.8gm Which ball do you think is more dense? The golf ball or the ping pong ball? Why? Density • Mass per unit volume Which box has a greater density? A B • Box A has a greater density than Box B • Why? Because it has a greater mass (more matter) • Density of water = 1 g/mL • Equation = mass = m volume v #1: What is the density of a metal block that has a mass of 525g and the volume is 50cm3? Mass: 525g 3 Volume: 50cm D=m v D = 525 g 3 50 cm 3 D = 10.5 g/cm #2: The metal block was split in half. The mass of each half is 262.5g and the volume of each half is 25cm3. Calculate the density. Mass: 262.5g Volume: 25cm3 D=m v D = 262.5 g 3 25 cm 3 D = 10.5 g/cm What is the block made of? Silver = 10. 5 g/cm3 • Density NEVER CHANGES!!! M = 20 g V = 10 mL Density = 20/10 = 2 g/mL Cut the block in half M = 10 g V = 5 mL Density = 10/5 = 2g/mL It remains the same !!!! • Each pure substance has it’s own density. Topic: Measurement Aim: Describe density and how it is measured. Do Now: 1. Take out temperature reading for me to check. 2. Take out Measuring Volume ditto and complete 4 – 9. 3. Take out the blue Density Sheet and complete #3. HW: Graphing Ditto Side 2 47mL 56mL 35mL 73mL 43mL 7.6mL #3 The mass of a marble is 8.8 g. It has a volume of 2 mL. What is the density? Mass: 8.8g Volume: 2mL D=m v D = 8.8 g 2 mL D = 4.4 g mL Why will an object float or sink in water? More dense than water Less dense than water Less dense than water More dense than water • FLOATS: object’s density is LESS than the liquid’s density • SINKS: object’s density is GREATER than the liquid’s density 1.Which liquid is the MOST dense? Support your answer. 2.Which liquid is the LEAST dense? Support your answer. 1. Which LIQUID is LEAST dense? 2. Which LIQUID is MOST dense? 3. Which OBJECT is LEAST dense? 4. Which OBJECT is MOST dense? 1. Which LIQUID is LEAST dense? • Corn oil • It’s floating at the top 2. Which LIQUID is MOST dense? • Mercury • It’s at the bottom. 3. Which OBJECT is LEAST dense? • Wood • It’s floating at the top 4. Which OBJECT is MOST dense? • Copper wire • It’s at the bottom. Why does warm air rise? Warm air rises bc it is less dense than cold air which sinks. Let’s summarize… 1. Identify the equation for determining density. 2. Describe what do you know about the density of different substances. 3. Identify the density of water. 4. What would happen to the density of a substance if it was cut into six pieces? 5. Why do substances float in water? 6. Why do substances sink in water? The units of density could be 1. milliliters per gram 2. milliliters 3. gram 4. grams per milliliter What is the density of a 40-gram object with a volume of 20 milliliters? 1. 2 g 2. 2 ml/g 3. 2 g/ml 4. 2 ml/g A cube is 1 cm on each side and has a mass of 2 grams. Will it float? 1. yes 2. no 3. The only way to tell is to put it in water. . The density of water is 1. 1 mL/g. 2. 1 g/L. 3. 1 g/mL. 4. 1 kg/mL. An object that floats in water has a density of 1. less than 1 g/mL. 2. equal to 1 g/mL. 3. greater than 1 g/mL. 4. equal to 10 g/mL. 1. Will an object with a 3 density of 3.4gm/cm sink or float in a cup of water? Explain why. 2. Will an object with a 3 density of.086gm/cm sink or float in a cup of water? Explain why. Review: Which piece of laboratory equipment would be used to obtain the most accurate measure of the volume of a glucose solution? 1. triple beam balance 2. graduated cylinder 3. beaker 4. metric ruler Which piece of equipment could be used to determine the mass of a frog? 1. triple beam balance 2. graduated cylinder 3. beaker 4. metric ruler Mass is best defined as the 1. size of an object 2. density of an object 3. amount of matter in an object 4. weight of an object The amount of space an object takes up is known as its 1. mass 2. density 3. volume 4. matter The units for the volume of a solid is 1. mL 2. mm 3. L 3 4. cm The basic unit of volume in the metric system is the 1. kilogram 2. gallon 3. liter 4. mass • http://ippex.pppl.gov/interactive/matter/den slab.html