My Chemistry Project
1.According to the kinetic theory, both the particles in gases and the particles in liquids have kinetic energy. This energy allows the particles in gases and liquids to flow past one another, as shown in Figure 13.5. Substances that can flow are referred to as fluids. The ability of gases and liquids to flow allows them to conform to the shape of their containers.
Figure 13.5 Both liquids and gases can flow. The liquid on the left is colored water. The gas on the right is bromine vapor. If a gas is denser than air, it can be poured from one container into another. These pictures were taken in a fume hood because bromine is both toxic and corrosive. 2. Figure 13.6a eventually moves into the air. The conversion of a liquid to a gas or vapor is called vaporization. When such a conversion occurs at the surface of a liquid that is not boiling, the process is called evaporation. Most of the molecules in a liquid don’t have enough kinetic energy to overcome the attractive forces and escape into the gaseous state. During evaporation, only those molecules with a certain minimum kinetic energy can escape from the surface of the liquid. Even some of the particles that do escacape collide with molecules in the air and rebound into the liquid.
Figure 13.6 The process of evaporation has a different outcome in an open system, such as a lake, than in a closed system, such as a terrarium. (a) In an open container, molecules that evaporate can escape from the container. (b) In a closed container, the molecules cannot escape. They collect as a vapor above the liquid. Some molecules condense back into a liquid.
3. Most solid substances are crystalline. In a crystal the particles are arranged in an orderly, repeating, three-dimensional pattern called a crystal lattice. Figure 13.10 shows part of the crystal lattice in sodium chloride. The shape of a crystal reflects the arrangement of the particles within the solid.
Figure 13.10 The orderly arrangement of sodium and
Figure 13.5 Both liquids and gases can flow. The liquid on the left is colored water. The gas on the right is bromine vapor. If a gas is denser than air, it can be poured from one container into another. These pictures were taken in a fume hood because bromine is both toxic and corrosive. 2. Figure 13.6a eventually moves into the air. The conversion of a liquid to a gas or vapor is called vaporization. When such a conversion occurs at the surface of a liquid that is not boiling, the process is called evaporation. Most of the molecules in a liquid don’t have enough kinetic energy to overcome the attractive forces and escape into the gaseous state. During evaporation, only those molecules with a certain minimum kinetic energy can escape from the surface of the liquid. Even some of the particles that do escacape collide with molecules in the air and rebound into the liquid.
Figure 13.6 The process of evaporation has a different outcome in an open system, such as a lake, than in a closed system, such as a terrarium. (a) In an open container, molecules that evaporate can escape from the container. (b) In a closed container, the molecules cannot escape. They collect as a vapor above the liquid. Some molecules condense back into a liquid.
3. Most solid substances are crystalline. In a crystal the particles are arranged in an orderly, repeating, three-dimensional pattern called a crystal lattice. Figure 13.10 shows part of the crystal lattice in sodium chloride. The shape of a crystal reflects the arrangement of the particles within the solid.
Figure 13.10 The orderly arrangement of sodium and