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What is the characteristic of the atomic arrangement in a crystalline solid?
What is the characteristic of the atomic arrangement in a crystalline solid?
What is the primary function of the unit cell in describing crystal structure?
What is the primary function of the unit cell in describing crystal structure?
What distinguishes a polycrystalline solid from an amorphous solid?
What distinguishes a polycrystalline solid from an amorphous solid?
What is the characteristic of the electrical conductivity of an ionic solid?
What is the characteristic of the electrical conductivity of an ionic solid?
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How do the atoms or molecules in an amorphous solid arrange themselves?
How do the atoms or molecules in an amorphous solid arrange themselves?
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What is the characteristic of the hardness of a metallic solid?
What is the characteristic of the hardness of a metallic solid?
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What is the characteristic of the melting point of a covalent solid?
What is the characteristic of the melting point of a covalent solid?
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What is the primary difference between a crystalline solid and an amorphous solid?
What is the primary difference between a crystalline solid and an amorphous solid?
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What is the scientific term for a finite array of points in three-dimensions in which every point has an identical environment as any point in the array?
What is the scientific term for a finite array of points in three-dimensions in which every point has an identical environment as any point in the array?
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What is the type of bond that involves the sharing of a pair of valence electrons by two atoms?
What is the type of bond that involves the sharing of a pair of valence electrons by two atoms?
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What is the law that presents a simple explanation of the diffracted beams from a crystal?
What is the law that presents a simple explanation of the diffracted beams from a crystal?
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What is the term for a solid that is not arranged in a regular order, as are those in crystalline solids?
What is the term for a solid that is not arranged in a regular order, as are those in crystalline solids?
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What is the type of defect that consists of a vacancy and an interstitial pair?
What is the type of defect that consists of a vacancy and an interstitial pair?
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What is the method that is useful for studying samples that are difficult to obtain in single crystal form?
What is the method that is useful for studying samples that are difficult to obtain in single crystal form?
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What is the type of crystal system that has a ≠ b ≠ c and α ≠ β ≠ γ ≠ 90?
What is the type of crystal system that has a ≠ b ≠ c and α ≠ β ≠ γ ≠ 90?
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What is the term for a region of atomic disorder in a lattice only a few atomic diameters wide?
What is the term for a region of atomic disorder in a lattice only a few atomic diameters wide?
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What is the type of symmetry operation that combines a rotation with a reflection at a plane perpendicular to the rotation axis?
What is the type of symmetry operation that combines a rotation with a reflection at a plane perpendicular to the rotation axis?
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What is the term for the symbolic vector representation for the orientation of an atomic plane in a crystal lattice?
What is the term for the symbolic vector representation for the orientation of an atomic plane in a crystal lattice?
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What is the number of atoms in a simple cubic unit cell?
What is the number of atoms in a simple cubic unit cell?
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What is the number of atoms in a face-centered cubic unit cell?
What is the number of atoms in a face-centered cubic unit cell?
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Which type of crystalline solid consists of atoms held together by intermolecular forces?
Which type of crystalline solid consists of atoms held together by intermolecular forces?
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What is the advantage of X-ray diffraction in determining the structure of crystalline materials?
What is the advantage of X-ray diffraction in determining the structure of crystalline materials?
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What is the symmetry operation that involves reflection through a plane?
What is the symmetry operation that involves reflection through a plane?
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What is the type of crystalline solid that consists of positive cores of atoms held together by a surrounding sea of electrons?
What is the type of crystalline solid that consists of positive cores of atoms held together by a surrounding sea of electrons?
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What is the disadvantage of X-ray diffraction in determining the structure of crystalline materials?
What is the disadvantage of X-ray diffraction in determining the structure of crystalline materials?
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What is the number of atoms in a body-centered cubic unit cell?
What is the number of atoms in a body-centered cubic unit cell?
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Study Notes
Types of Solids
- Molecular solids: consist of atoms or molecules held together by intermolecular forces, e.g., dry ice (CO2)
- Metallic solids: consist of positive cores of atoms held together by a surrounding sea of electrons, e.g., copper, iron
- Ionic solids: consist of cations and anions held together by electrical attraction, e.g., NaCl
- Covalent solids: consist of atoms held together by a large network or chains of covalent bonds, e.g., diamond, graphite
Properties of Solids
- Melting point: variable for ionic solids, high to very high for metallic solids, very high for covalent solids
- Hardness: soft for molecular solids, malleable for ionic solids, hard for metallic solids, very hard for covalent solids
- Electrical conductivity: nonconducting for molecular solids, conducting for ionic solids, nonconducting for metallic solids (solid), conducting for metallic solids (liquid), usually nonconducting for covalent solids
Crystalline Solids
- Crystalline solids: have a regular arrangement of atoms, have a periodic structure, and have a high degree of order over many atomic distances
- Amorphous solids: do not have a regular arrangement of atoms, are made up of randomly oriented atoms, and have a low degree of order
- Polycrystalline solids: have a high degree of order over many atomic distances, but are made up of many small crystals or grains
Unit Cell
- The unit cell is the basic structural unit or building block of the crystal structure
- The unit cell is the smallest unit of a crystal that, if repeated, could generate the whole crystal
- The unit cell has a lattice parameter that describes the crystal structure
X-Ray Diffraction
- X-ray diffraction is a nondestructive technique used to study crystal structures
- Uses: differentiation between crystalline and amorphous materials, determination of the structure of crystalline materials, determination of the orientation of single crystals, determination of the texture of poly-grained materials
- Advantages: cheapest, most convenient, and widely used method, not absorbed very much by air
- Disadvantages: does not interact very strongly with lighter elements
Cubic System
- Simple cubic: has one atom per unit cell
- Body-centered cubic: has two atoms per unit cell
- Face-centered cubic: has four atoms per unit cell
Symmetry Operations
- Symmetry operations: operations that take the crystal into itself
- Types of symmetry operations: rotation, reflection, inversion, rotation-inversion, glide reflection, screw translation
Crystal Defects
- Types of defects: vacancy, interstitial, Frenkel, Schottky, edge dislocation, screw dislocation
- Frenkel defect: a combination of vacancy and interstitial defects
- Schottky defect: a cation vacancy – anion vacancy pair
- Edge dislocation: a type of dislocation where the Burger vector is perpendicular to the dislocation line
- Screw dislocation: a type of dislocation where the Burger vector is parallel to the dislocation line
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Description
This quiz covers the characteristics of different types of solids, including their melting points, hardness, and electrical conductivity. Identify the properties of molecular, ionic, metallic, and covalent solids.
