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67 Cards in this Set
- Front
- Back
Ceramics are typically very hard - true or false?
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True
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_________ are typically organic materials - ceramics or polymers?
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polymers
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The study of materials is called:
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metallurgy
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The name _________ comes from the Greek word for “burn earth”
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ceramics
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A combination of two or more metals or a metal and a nonmetal is __________
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polymer
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_______ Number is the number of protons in the nucleus of an atom
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atomic number
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Anion is a __________ charged ion produced when an atom, usually of a non-metal, accepts one or more electrons
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anion is negatively charged
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Atomic number is the number of ________ in an atom
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protons
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Pauli’s exclusion principle states that no two electrons have have the same set of four quantum numbers - true or false?
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true
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_______ quantum number is a quantum number representing the energy level of the electron
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principal
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Isotopes are atoms of the same element that have the same number of ________ but not the same number of neutrons
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protons
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Steels contain ________ than 2% of carbon - more or less
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less
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Avogadro’s number corresponds to the number of ______ needed to create a mass in units of grams numerically equal to the atomic mass in amu of the substance under consideration
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atoms
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One atom of oxygen has a mass of 16 amu; what is the mass in grams of one mole of oxygen atoms
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16 g
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Outer electrons (high energy electrons) are the valence electrons - true or false?
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true
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Vand der Waals are _______ bonds - primary, secondary, tertiary?
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secondary
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The mechanical properties of metals are significantly different that those of ionic and covalent networked materials - true or false?
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true
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Transition metals have what kind of bonding?
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mixed metallic covalent
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ionic solids generally have ______ melting temperatures - low or high?
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high
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Which is not a primary bond? A) covalent b) hydrogen c) ionic d) metallic
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b) hydrogen!
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When atoms release electrons they have a positive charge and are called _____
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cations
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1 amu/atom = 1 g/mol - true or false?
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false
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covalent bonds are very weak - true or false
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false
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Sodium chloride is the classic covalent material
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true
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_________ is the fraction of the volume of a unit cell that is occupied by a “hard sphere” atoms or ions
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atomic packing factor (APF)
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The atomic packing factor for FCC is ______
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0.74
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For the BCC crystal structure, each corner atom is shared among _______ unit cells
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8 unit cells
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the atomic packing factor for BCC is ____
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0.68
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For the FCC crystal structure, each corner atom is shared among _____ unit cells
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8 unit cells
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The equivalent of ______ atoms is contained in each HCP unit cell
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6 atoms
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APF is the volume of the unit cell divided by the volume of atoms in each selected unit cell - true or false?
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false
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Materials that have more than one crystal structure are called ______
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allotropic
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The _______ is the number of atoms touching a particular atom, or the number of nearest neighbors for that particular atom
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coordination number
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__________ are long, thin grains in solidified polycrystalline structure
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columnar grains
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Iron exists in _____
(number) crystal structure over the temperature range from room temperature to its melting point |
2 crystal structures
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_____ Law gives the relationship among the angular positions of the reinforced diffracted beams in terms of the wavelength of the incoming X-ray radiation and of the interplanar spacing of the crystal planes
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Bragg's Law
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_______ Nucleation is a liquid melt occurs when the metal itself provides the atoms needed to form a nuclei
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homogeneous
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______ nucleation is nucleation that occurs in a liquid on the surfaces of its container, insoluble, impurities, and other structural material that lower the critical free energy required to form a stable nucleus
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heterogeneous
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Continuous casting has been fabricated in _______
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cast houses
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Nuclei is small particles of a new phase formed by a phase change that can grow until the phase change is complete - true or false
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true
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______ is a single crystal in a polycrystalline aggregate
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grain
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columnar grains are long, thin grains in a solidified polycrystalline structure - true or false?
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true
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To produce cast ingots with a fine grain size, grain refiners are usually added to the liquid metal before castings - true or false
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true
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There are ____ main types of dislocations (number)
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2
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Dislocations are ______ imperfections
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line imperfections
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_____ is a single crystal in a polycrystalline aggregate
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grain
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grain boundaries are _____
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surface imperfections
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the displacement distance of the atoms around the dislocation is called _____
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burgers! Yum!
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_____ is a point imperfection in a crystal lattice where an atom is missing from an atomic site
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vacancy
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______ solid solution is a solid solution in which solute atoms of one element can replace those of solvent atoms of another element
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substitutional
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_____ grains are long, thin grains in solidified polycrystalline structure
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columnar grains
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crystal lattice imperfections are classified according to their geometry and shape - true or false?
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true
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There are ____ types of solid solutions (number)
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2
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What are the five main classes of engineering materials?
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metals, ceramics, polymers, composites, and electronics
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Properties of metals
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strong, hard; can be strengthened through alloying, mechanical and heat treatment; ductile
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properties of polymers
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plastics; noncrystalline organic molecules; poor conductors, used as insulators; wide range of strength and ductility
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properties of ceramics
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high resistance to hear, brittle; strong in compression; involve chemical bonding of metallic and nonmetallic elements; good insulators
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properties of composites
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combine favorable properties of multiple classes of materials; two types: fiborous and particulare
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properties of electronics
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not a large volume; silicon is very important
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Describe smart materials
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smart materials can sense external stimuli and respond by changing mechanical or electrical properties, or appearance
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simple diffusion is defined as the movement of _____
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molecules from areas of higher concentraion to areas of lower concentraion
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when sugar is mixed with water, equilibrium is reached when
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the dissolved sugar molecules are evenly distributed throughout the solution
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the rate of diffusion is affected by:
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temperature, size of molecules, steepness of concentration gradient
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the molecules in a solid lump of sugar do not move - true or false
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false
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diffusion is one of the processes whereby materials are exchanged between a cell and its environment - true or false?
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true
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What are the names of the 4 quantum numbers?
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Principal quantum number, orbital, magnetic, spin
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What is the structure of something with 18 electrons
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1s^2 2s^2 2p^6 3s^2 3p^6
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