Chemistry 13.3Chemistry 13.3

The Nature of SolidsThe Nature of Solids

In 1985, scientists In 1985, scientists discovered a new form discovered a new form of carbon. They called of carbon. They called this form of carbon this form of carbon buckminsterfullerene, buckminsterfullerene, or buckyball for or buckyball for short. You will learn short. You will learn how the arrangement of how the arrangement of particles in solids particles in solids determines some determines some general properties of general properties of solids.solids.

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A Model for SolidsA Model for Solids

A Model for SolidsA Model for Solids

• How are the structure and How are the structure and properties of solids related?properties of solids related?

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A Model for SolidsA Model for Solids

•The general properties of The general properties of solids reflect the orderly solids reflect the orderly arrangement of their arrangement of their particles and the fixed particles and the fixed locations of their particles.locations of their particles.

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A Model for SolidsA Model for Solids

The melting point The melting point (mp) is the (mp) is the temperature at which a solid changes temperature at which a solid changes into a liquid.into a liquid.

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Crystal Structure and Unit CellsCrystal Structure and Unit Cells

Crystal Structure and Unit Crystal Structure and Unit CellsCells

• What determines the shape of a What determines the shape of a crystal?crystal?

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Crystal Structure and Unit CellsCrystal Structure and Unit Cells

In a In a crystal,crystal, the particles are the particles are arranged in an orderly, repeating, arranged in an orderly, repeating, three-dimensional pattern called a three-dimensional pattern called a crystal lattice.crystal lattice.

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Crystal Structure and Unit CellsCrystal Structure and Unit Cells

•The shape of a crystal The shape of a crystal reflects the arrangement of reflects the arrangement of the particles within the the particles within the solid.solid.

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Crystal Structure and Unit CellsCrystal Structure and Unit Cells

• Crystal SystemsCrystal Systems A crystal has sides, or faces. A crystal has sides, or faces. Crystals are classified into seven Crystals are classified into seven crystal systems. crystal systems.

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Crystal Structure and Unit CellsCrystal Structure and Unit Cells

These minerals show four out of the These minerals show four out of the seven crystal systems.seven crystal systems.

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Crystal Structure and Unit CellsCrystal Structure and Unit Cells

Three kinds of unit cells can make up Three kinds of unit cells can make up a cubic crystal system.a cubic crystal system.

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Crystal Structure and Unit CellsCrystal Structure and Unit Cells The smallest group of particles The smallest group of particles within a crystal that retains the within a crystal that retains the geometric shape of the crystal is geometric shape of the crystal is known as a known as a unit cell.unit cell.

• A crystal lattice is a repeating array of A crystal lattice is a repeating array of any one of fourteen kinds of unit cells.any one of fourteen kinds of unit cells.

• There are from one to four types of unit There are from one to four types of unit cells that can be associated with each cells that can be associated with each crystal system.crystal system.

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Crystal Structure and Unit CellsCrystal Structure and Unit Cells

•Allotropes Allotropes AllotropesAllotropes are two or more are two or more different molecular forms of different molecular forms of the same element in the same the same element in the same physical state.physical state.

• Allotropes have different Allotropes have different properties because their properties because their structures are different.structures are different.

• Only a few elements have Only a few elements have allotropes.allotropes.

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Crystal Structure and Unit CellsCrystal Structure and Unit Cells

Carbon AllotropesCarbon Allotropes

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Crystal Structure and Unit CellsCrystal Structure and Unit Cells

•Non-Crystalline SolidsNon-Crystalline Solids An An amorphous solidamorphous solid lacks an lacks an ordered internal structure.ordered internal structure.•Rubber, plastic, asphalt, and Rubber, plastic, asphalt, and glass are amorphous solids. glass are amorphous solids.

•A A glassglass is a transparent is a transparent fusion product of inorganic fusion product of inorganic substances that have cooled substances that have cooled to a rigid state without to a rigid state without crystallizing.crystallizing.

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13.3 Section Quiz.13.3 Section Quiz.

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13.3 Section Quiz13.3 Section Quiz

• 1.1. A solid will melt whenA solid will melt when all the particles have the same kinetic energy.all the particles have the same kinetic energy.

bonds form between the particles.bonds form between the particles.

disruptive vibrations overcome attractive disruptive vibrations overcome attractive forces.forces.

attractions overcome disruptive vibrations.attractions overcome disruptive vibrations.

13.3 Section Quiz13.3 Section Quiz• 2.2. Which of the following affect the shape of crystals?Which of the following affect the shape of crystals?• (1) angles between the faces(1) angles between the faces• (2) number of edges of equal length per face(2) number of edges of equal length per face• (3) size of the crystal(3) size of the crystal

(1) only(1) only (2) only(2) only (3) only(3) only (1) and (2)(1) and (2)

13.3 Section Quiz13.3 Section Quiz

• 3.3. Allotropes have different Allotropes have different properties becauseproperties because

their atoms are arranged in different their atoms are arranged in different patterns.patterns.

they are composed of different they are composed of different elements.elements.

they are in different states.they are in different states. they consist of different isotopes of they consist of different isotopes of the same element.the same element.

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