Which statement is true about the efficiency of atom packing in FCC and HCP structures? Question 19 options: FCC structures have a higher APE than HCP structures. C. FCC and HCP structures both have an APE of 74% FCC and HCP structures both have an APE of 68%.
Question
Which statement is true about the efficiency of atom packing in FCC and HCP structures?
Question 19 options:
FCC structures have a higher APE than HCP structures.
C. FCC and HCP structures both have an APE of 74%
FCC and HCP structures both have an APE of 68%.
Solution
Para responder a esta pregunta, primero debemos entender qué es el APE (Atomic Packing Efficiency) y cómo se relaciona con las estructuras FCC (Face-Centered Cubic) y HCP (Hexagonal Close-Packed).
-
Definición de APE: El APE es una medida de la fracción del volumen de una celda unitaria que está ocupada por átomos. Se expresa como un porcentaje.
-
Estructura FCC: En una estructura cúbica centrada en las caras (FCC), los átomos están dispuestos de tal manera que cada celda unitaria contiene 4 átomos. La eficiencia de empaquetamiento atómico (APE) para FCC es del 74%.
-
Estructura HCP: En una estructura hexagonal compacta (HCP), los átomos también están dispuestos de manera muy eficiente. La celda unitaria de HCP contiene 6 átomos. La eficiencia de empaquetamiento atómico (APE) para HCP también es del 74%.
Ahora, revisemos las opciones dadas:
-
Opción A: "FCC structures have a higher APE than HCP structures." Esto no es correcto porque ambas estructuras tienen la misma APE del 74%.
-
Opción B: "FCC and HCP structures both have an APE of 74%." Esta opción es correcta, ya que ambas estructuras tienen una eficiencia de empaquetamiento del 74%.
-
Opción C: "FCC and HCP structures both have an APE of 68%." Esto no es correcto porque ambas estructuras tienen una APE del 74%, no del 68%.
Por lo tanto, la respuesta correcta es:
C. FCC and HCP structures both have an APE of 74%.
Similar Questions
QUESTION TWO (20 MARKS)a. Briefly explain why HCP metals are typically more brittle than FCC and BCC metals.(4 marks)b. The key to strengthening metals is in hindering the motion of dislocations. Briefly describethe four strengthening mechanisms in metals. Be sure to explain how dislocations areinvolved in each of the strengthening mechanisms. (8 marks)c. In one of the four strengthening mechanisms above (Question 1a), identify anothermechanical property that is significantly degraded, and explain why this has occurred eventhough strength is increased. (2 marks)d. Determine whether or not it is possible to cold work steel to give a minimum Brinellhardness of 225, and at the same time have a ductility of at least 12%EL. Justify yourdecision. Use equation 1 and Figure 1. (6 marks)𝑇𝑆(𝑀𝑃𝑎) = 3.45 𝑥 𝐻𝐵……………(1)Where TS = Tensile strength and HB = Brinnel hardnessFigure 1: For 1040 steel, brass, and copper, (a) the increase in yield strength, (b) theincrease in tensile strength, and (c) the decrease in ductility (%EL) with per cent (%) coldwork.
Which one of the following statements is false?Group of answer choicesAll silicon atoms contain 14 protons.Protons and neutrons have a much greater mass than electrons.Different isotopes of the same element contain different numbers of protons.The magnesium cation (Mg2+) has 10 electrons.The chlorine atom gains one electron to become the chloride anion (Cl–).
he number of atoms per unit cell, coordination number, and atomic packing factor, for a FCC crystal are……………
The number of atoms per unit cell, coordination number, and atomic packing factor, for a FCC crystal are……………a.4, 12, and 0.74b.1, 6, and 0.52c.2, 8, and 0.68d.6, 12, and 0.74
Which one of the following is false? Chlorine (Z=17) has a smaller radius than aluminum (Z=13). Carbon (Z=6) has a higher first ionization energy than boron (Z=5). Potassium (Z=19) has a higher electron affinity than sodium (Z=11). Beryllium (Z=4) has a larger radius than carbon (Z= 6). Chlorine (Z=17) is more electronegative than iodine (Z=53).
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.