Slide 1 of 25 Density 3.4

© Copyright Pearson Prentice Hall Slide 2 of 25 Density If you think that these lily pads float because they are lightweight, you are only partially correct. The ratio of the mass of an object to its volume can be used to determine whether an object floats or sinks in water. 3.4

© Copyright Pearson Prentice Hall Density > Slide 3 of 25 Determining Density What determines the density of a substance? 3.4

© Copyright Pearson Prentice Hall Slide 4 of 25 Density > Determining Density Density is the ratio of the mass of an object to its volume. 3.4

© Copyright Pearson Prentice Hall Slide 5 of 25 Density > Determining Density Each of these 10-g samples has a different volume because the densities vary. 3.4

© Copyright Pearson Prentice Hall Slide 6 of 25 Density > Determining Density Density is an intensive property that depends only on the composition of a substance, not on the size of the sample. 3.4

© Copyright Pearson Prentice Hall Slide 7 of 25 Density > Determining Density The density of corn oil is less than the density of corn syrup. For that reason, the oil floats on top of the syrup. 3.4

© Copyright Pearson Prentice Hall Density > Slide 8 of 25 Density and Temperature How does a change in temperature affect density? 3.4

Slide 9 of 25 © Copyright Pearson Prentice Hall Density > Density and Temperature Experiments show that the volume of most substances increases as the temperature increases. Meanwhile, the mass remains the same. Thus, the density must change. The density of a substance generally decreases as its temperature increases. 3.4

© Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 10 of

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© Copyright Pearson Prentice Hall Slide 18 of 25 Section Quiz -or- Continue to: Launch: Assess students’ understanding of the concepts in Section Section Assessment 3.4

© Copyright Pearson Prentice Hall Slide 19 of Section Quiz 1. If 50.0 mL of corn syrup have a mass of 68.7 g, the density of the corn syrup is a g/mL. b g/mL. c.1.36 g/mL. d.1.37 g/mL.

© Copyright Pearson Prentice Hall Slide 20 of Section Quiz 2. What is the volume of a pure gold coin that has a mass of 38.6 g? The density of gold is 19.3 g/cm 3. a cm 3 b.2.00 cm 3 c.38.6 cm 3 d.745 cm 3

© Copyright Pearson Prentice Hall Slide 21 of Section Quiz 3. As the temperature increases, the density of most substances a.increases. b.decreases. c.remains the same. d.increases at first and then decreases.

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