Presentation on theme: "Cube Activity pg. 69 Question: Do cubes of exactly the same size and shape have the same mass?"— Presentation transcript:
1Cube Activity pg. 69Question: Do cubes of exactly the same size and shape have the same mass?
2Analysis Questions Description of cube –color, size, shape 1) Give an explanation as WHY one feels heavier. (what causes an object to have a different mass from another)2)Description of cube –color, size, shapePicture of arrangement of the moleculesMass (g)Volume (cm3)1)Gold cube13615.622) Silver cube45
3Correct ArrangementHeavy substance-smaller and more compacted moleculesLighter substance-larger and lessCompacted molecules
4Density Lab pg 70Problem: How are the volume and mass of a substance related?Hypothesis: If the molecules of one object are smaller and more compact than another, then its density will be greater because there are more molecules in each volume of the denser object.
5MaterialsTwo sets of metals of different shapesGraduated CylinderMetric RulerWaterMass balance
6ProceduresWeigh each shape on a mass balance BEFORE measuring the volumeRecord each shape’s mass in the data tableMeasure the cubes’ volume using the metric ruler (V=l*w*h)Measure the volume of the other two shapes with the graduated cylinder.Record the volumes in the data table.Graph the data. Create a Volume vs. Mass graph.Make a best fit line for each metal.Find the slope of BOTH lines.
8Conclusion-Big Idea from metals Lab pg71. Objects with the same volume but different masses have Different-DENSITIESDENSITY:The relationship between the mass of the substance and how much space it takes up.OR how compact the molecules are in a certain amount of spaceAnalogy-House PartyWHY DO OBJECTS HAVE DIFFERENT DENSITIES?The mass of atoms, their size, and how they are arranged determine the density of a substance.
9What two measurements do you need to find to solve for density= MASS and VOLUME Formula for Density= Mass/VolumeUnits= g/cm3 or g/mLHow do you find density from your graph? SLOPE3 equations=Densities of known substances: Gold 19.3g/cm3 , Steel 7.6g/cm3 Cooking Oil 0.92g/mL
10Density Questions-whiteboard and Pg. 36 1) Why do objects have different densities?2) How might the factors listed in question #1 cause a substance to have a higher density? HINT: Use your answer to #1 to help3) How might the factors listed in question #1 cause a substance to have a lower density? HINT: Use your answer to #1 to help4) Draw the arrangement of the molecules for Copper that has a density of 8.9g/cm35) Draw the arrangement of the molecules for Aluminum that has a density of 2.7g/cm3
11Pretest pg.31The following rods have the SAME MASS but different VOLUMESPredict the densities of each sample by writing- Least dense, Medium dense, Most denseExplain why you think each rod is either the most, medium, or least dense
12Unknown Activity pg. 38Question: Do substances with the same mass but different volumes have the same density?
13Description of the cube-color and shape Mass (g) Volume (cm3 ) Calculated Densityg/cm31)2)1)2) Use your calculated density to answer: Do objects with the same mass and different volumes HAVE different DENSIITIES?3) Draw a picture of the arrangement of the particles for each cube.4) what can you conclude about the density with objects with the same mass but different volumes?Pick one-a) their densities will be the same,b) the one with the larger volume will have the lower density,c) the one with the larger volume will have the higher density,d) the one with the larger density will be twice as dense.
14Pg.29 Identifying Unknown Metals Lab Properties of a substance- how an object looks, feels, act, what it is used for.Examples- color, texture, smell, mass, volume, density, size, shape, melting point, boiling point
15Brainstorm: We have a bucket of metals Brainstorm: We have a bucket of metals. What property(s) can we use to help identify them?Problem: What is the identification of each metal?Hypothesis: If we find the mass and the volume of each metal, then we can identify them because each metal has a specific relationship which is ___________________.We will find the relationship between mass and volume by using our graph to find the ______________.
16Data Data Table #1 Data Table #2 Data Table #3 Color/Description of MetalVolume (cm3)Mass (g)Color/Description of MetalVolume (cm3)MassColor/Description of MetalVolume (cm3)Mass
17Graph Create one graph with three lines! Graph each data table separately and then create a best fit line.Use different colors.
18Data Evaluation DATA EVALUATION You will have three data evaluations for each LINE! Do all four steps for each line.Please also write your slope on the line on the graph.
19Results IDENTIFICATIONS Use the information on the board to identify your metalMetalReal Name
20Periodic table Look at the periodic table. Which atoms do you think have the greatest density?Actually the smaller more compacted atoms are more dense.Density explains why certain atoms make up certain substances. For examplePlastic is made from carbon and hydrogen. These atoms are very light.
21Based on what you know about the size, mass, and arrangement of atoms, explain why a sample of sulfur is more dense than a sample of calcium.
22AnswerEven though a sulfur atom has less mass than a calcium atom, many more sulfur atoms can pack together in a certain amount of space.This gives sulfur more mass per volume than calcium, making it more dense.
23Analysis questions continue 1) The size, mass, and arrangement of atoms affect the density of a substance.If a substance has a high density, what can you guess about the size, mass, and arrangement of the atoms that make up the substance?2) If a substance has a low density, what can you guess about the size, mass, and arrangement of the atoms that make up the substance?