MTL 200 Final UPDATED Exam Questions
and CORRECT Answers
What are ceramics? - Correct Answer- Ceramics are elements composed of at least two
elements, often more, with complex crystal structures that range from purely ionic to totally
covalent.
Anisotropy - Correct Answer- directionality of properties
What influences the crystal structure of ceramics? - Correct Answer- The electrical charge of
ions and the relative sizes of the anion and cation.
Why must a ceramic molecule be neutral? - Correct Answer- The net charge across the cation
and anion must be 0, and the whole ceramic molecule must be neutral.
What do cations and anions prefer in terms of nearest neighbors? - Correct Answer- Cations
prefer to have as many nearest neighbor anions as possible, and anions prefer to have as
many cations as possible.
What are the most common coordination numbers in ceramics? - Correct Answer- The most
common coordination numbers in ceramics are 4, 6, and 8
What happens when the ratio of the radii is greater than 1? - Correct Answer- The
coordination number is 12.
What are the 3 types of ceramic crystal structures? - Correct Answer- AX, AmXp, and
AmBnXp Type
What are the 3 subdivisions of AX- Type ceramic structure? - Correct Answer- 1. Rock salt
structure (NaCl)
2. Cesium Chloride Structure (CsCl)
3. Zinc Blende Structutre (ZnS)
, What is the main relationship between the unit cell and rock salt structure (NaCl) and its
coordination number? - Correct Answer- The main relationship is 2(r_c + r_a) = a.
Its coordination number is 6.
How many anions and cations do you have in a Rock Salt Structure? - Correct Answer- 4
anions and 4 cations.
What is the main relationship between the unit cell and cesium chloride structure (CsCl)and
its coordination number? - Correct Answer- The main relationship is 2(r_c + r_a) = sqrt(3)a.
Its coordination number is 8.
What is the main relationship between the unit cell and zinc blende structure (ZnS) and its
coordination number? - Correct Answer- The main relationship is 4(r_c + r_a) = sqrt(3)a.
Its coordination number is 4.
What is the equation for the volume of a sphere? - Correct Answer- V=4/3 πr³
What are the examples of ceramics with rock salt structure (NaCl)? - Correct Answer-
Examples include NaCl, MgO, MnS, LiF, and FeO.
What is the coordination number and structure of the CsCl structure? - Correct Answer-
Coordination number = 8, anions @ corners of a cube, single cation @ center.
What is the coordination number and structure of the zinc blende structure (ZnS)? - Correct
Answer- coordination number = 4, and each Zn is bonded to 4 S atoms. The structure is FCC.
What is the coordination number of AmXp-type ceramic? - Correct Answer- AX2
subdivision: coordination number is 8 and an example is CaF2, rc/ra = 0.8. (Ca - center, F -
corners)
and CORRECT Answers
What are ceramics? - Correct Answer- Ceramics are elements composed of at least two
elements, often more, with complex crystal structures that range from purely ionic to totally
covalent.
Anisotropy - Correct Answer- directionality of properties
What influences the crystal structure of ceramics? - Correct Answer- The electrical charge of
ions and the relative sizes of the anion and cation.
Why must a ceramic molecule be neutral? - Correct Answer- The net charge across the cation
and anion must be 0, and the whole ceramic molecule must be neutral.
What do cations and anions prefer in terms of nearest neighbors? - Correct Answer- Cations
prefer to have as many nearest neighbor anions as possible, and anions prefer to have as
many cations as possible.
What are the most common coordination numbers in ceramics? - Correct Answer- The most
common coordination numbers in ceramics are 4, 6, and 8
What happens when the ratio of the radii is greater than 1? - Correct Answer- The
coordination number is 12.
What are the 3 types of ceramic crystal structures? - Correct Answer- AX, AmXp, and
AmBnXp Type
What are the 3 subdivisions of AX- Type ceramic structure? - Correct Answer- 1. Rock salt
structure (NaCl)
2. Cesium Chloride Structure (CsCl)
3. Zinc Blende Structutre (ZnS)
, What is the main relationship between the unit cell and rock salt structure (NaCl) and its
coordination number? - Correct Answer- The main relationship is 2(r_c + r_a) = a.
Its coordination number is 6.
How many anions and cations do you have in a Rock Salt Structure? - Correct Answer- 4
anions and 4 cations.
What is the main relationship between the unit cell and cesium chloride structure (CsCl)and
its coordination number? - Correct Answer- The main relationship is 2(r_c + r_a) = sqrt(3)a.
Its coordination number is 8.
What is the main relationship between the unit cell and zinc blende structure (ZnS) and its
coordination number? - Correct Answer- The main relationship is 4(r_c + r_a) = sqrt(3)a.
Its coordination number is 4.
What is the equation for the volume of a sphere? - Correct Answer- V=4/3 πr³
What are the examples of ceramics with rock salt structure (NaCl)? - Correct Answer-
Examples include NaCl, MgO, MnS, LiF, and FeO.
What is the coordination number and structure of the CsCl structure? - Correct Answer-
Coordination number = 8, anions @ corners of a cube, single cation @ center.
What is the coordination number and structure of the zinc blende structure (ZnS)? - Correct
Answer- coordination number = 4, and each Zn is bonded to 4 S atoms. The structure is FCC.
What is the coordination number of AmXp-type ceramic? - Correct Answer- AX2
subdivision: coordination number is 8 and an example is CaF2, rc/ra = 0.8. (Ca - center, F -
corners)
