ACTUAL 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.