Materials Science Flashcards
how many electrons can be held in orbitals s, p, d, and f?
2, 6, 10, 14
what are valence electrons?
outermost shell of an electron cloud
What types of elements create ionic bonds?
metals and nonmetals
What happens to electrons in ionic bonding?
They are transferred from atoms with few valence electrons to atoms that have nearly full valence electrons.
What orbitals dominate covalent bonding?
S and P
What happens to electrons in covalent bonding?
They are shared by atoms to fill shells.
What happens to electrons in metallic bonding?
Electrons freely drift around in a “sea of electrons”
what is given by the equation (1-e^-(((Xa-Xb)^2)/4))x100
Percent ionic character
What kind of bonds are in amorphous structures?
Ionic and Covalent
What kind of bonds are in crystalline structures?
metallic and ionic
How many atoms are in a Body Centered Cubic (BCC) structure?
9
How many atoms are in a Face-Centered Cubic (FCC) structure?
14
How many atoms are in a Simple Cubic (SC) structure?
8
What is the difference between BCC (body centered cubic) and BCT (body entered tetragonal)?
BCT is not a cube and has rectangular faces.
What is the equation for Atomic Packing Factor (APF)?
(volume of atoms)/(volume of unit cell)
What is the equation for theoretical density?
(nA)/(VcNa); where n is the number of atoms per unit cell, A is atomic weight, Vc is volume of the unit cell, and Na is Avigadro’s number.
Rank the density of polymers, metals, and ceramics.
metals>ceramics>polymers
What is a vacancy point defect?
when an atom is missing in the structure of a solid, so other atoms move to fill in the space.
What is a interstitial point defect?
Extra atom squeezed into lattice. Can either be the same or different.
What is the lattice direction equation of the image?
Sketch the lattice direction vector based on the equations [100], [110] and [111].
What is the lattice plane of the image?
Sketch the lattice plane of (102)
What does the equation [uvw] represent?
A lattice direction.
