Chapter 6 Energy and Matter :1 Chapter 6 Energy and Matter 6.5 States of Matter Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings


Solids :2 Solids Solids have A definite shape. A definite volume. Particles that are close together in a fixed arrangement. Particles that move very slowly. Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings


Liquids :3 Liquids Liquids have An indefinite shape, but a definite volume. The same shape as their container. Particles that are close together, but mobile. Particles that move slowly. Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings


Gases :4 Gases Gases have An indefinite shape. An indefinite volume. The same shape and volume as their container. Particles that are far apart. Particles that move very fast. Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings


Three States of Water :5 Three States of Water Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings


Summary of the States of Matter :6 Summary of the States of Matter Property Solid Liquid Gas Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings


Learning Check :7 Learning Check Identify each as: S) solid L) liquid or G) gas. __ A. It has a definite volume, but takes the shape of the container. __ B. Its particles are moving rapidly. __ C. It fills the volume of a container. __ D. It has particles in a fixed arrangement. __ E. It has particles close together that are mobile.


Solution :8 Solution Identify each as: S) solid L) liquid or G) gas. L A. It has a definite volume, but takes the shape of the container. G B. Its particles are moving rapidly. G C. It fills the volume of a container. S D. It has particles in a fixed arrangement. L E. It has particles close together that are mobile.


Attractive Forces Between Particles :9 Attractive Forces Between Particles Forces that hold particles together in liquids and solids include Ionic compounds -ionic bonds Covalent compounds -Hydrogen bonds -Dipole-dipole attractions -Dispersion forces


Ionic Bonds :10 Ionic Bonds In ionic compounds, ionic bonds Are strong attractive forces. Hold positive and negative ions together. Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings


Dipole-Dipole Attractions and Hydrogen Bonds :11 Dipole-Dipole Attractions and Hydrogen Bonds In polar covalent compounds, dipole-dipole attractions Are attractive forces between positively and negatively charged ends of polar molecules. Are called hydrogen bonds when hydrogen atoms in one molecule are attracted to the strongly electronegative atoms F, O, or N in another molecule.


Dipole-Dipole Attractions :12 Dipole-Dipole Attractions Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings


Dispersion Forces :13 Dispersion Forces Dispersion forces are Weak attractions between nonpolar molecules. Caused by temporary dipoles that develop when electrons are not distributed equally. Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings


:14 Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings TABLE 6.8


Melting Points and Attractive Forces :15 Melting Points and Attractive Forces Ionic compounds require large amounts of energy to break apart ionic bonds. Thus, they have high melting points. Hydrogen bonds are the strongest type of dipole-dipole attractions. They require more energy to break than other dipole attractions. Dispersion forces are weak interactions and very little energy is needed to change state.


:16 Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings TABLE 6.7 Melting Points and Attractive Forces of Selected Substances


Learning Check :17 Learning Check Identify the main type of attractive forces for each: 1) ionic 2) dipole-dipole 3) hydrogen bonds 4) dispersion A. NCl3 B. H2O C. Br-Br D. KCl E. NH3


Solution :18 Solution Identify the main type of attractive forces for each: 1) ionic 2) dipole-dipole 3) hydrogen bonds 4) dispersion 2 A. NCl3 3 B. H2O 4 C. Br-Br 1 D. KCl 3 E. NH3