Ch. 10 Word Scramble
|
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Question | Answer |
Solids | 1. Covalent Network 2. Ionic 3. Metallic 4. Molecular Covalent (3 types of IMFs) |
covalent network | -the simultaneous attraction by covalent bonds of an atom by adjacent atoms within a 3-D lattice of atoms -very hard, very high melting point, insoluble in most ordianry solvents, nonconductors of electricity (b/c few open electrons) |
ionic | -simultaneous attraction of ion by surrounding ions of opposite charge within an ionic crystal lattice -crystalline solids, high melting and boiling points, dissolve in polar liquids to form conducting solution, electrical conductors as liquid |
metallic forces | -simultaneous attraction of free valence electrons by metallic cations -lustrous, malleable, good electrical conductors, wide range of melting points -electron sea models |
electron sea model | positive cations surrounded by a "sea" of MOBILE electrons |
molecular covalent | exists between nonmetals -Hydrogen bonding -Dipole-Dipole Forces -London dispersion forces |
Hydrogen bonding | -simultaneous attraction of a hydrogen ion (proton) by the electron pairs of adjacent N, O, F atoms -high melting solids, gases or liquids because of relatively strong intermolecular attraction |
Dipole-Dipole Forces | -the simultaneous attraction of a molecular dipole by the surrounding molecular dipoles. -a weak intermolecular force which exists in addition to the stronger dispersion forces, low melting solids, liquids,and gases |
intermolecular forces | weak interactions that occur between molecules |
surface tension | resistance of a liquid to an increase in its surface area |
capillary action | the spontaneous rising of a liquid in a narrow tube [cohesive / adhesive] |
cohesive forces | the intermolecular forces among the molecules of the liquid |
adhesive forces | the forces between the liquid molecular and their container |
viscosity | a measure of a liquid's resistance to flow -favor liquids with high IMF |
crystalline solids | highly regular arrangement of of their components |
amorphous solids | considerable disorder in their structures |
lattice | a 3D system of points designating the positions of the componenets (atoms, ions, or molecules) that make up the substance |
unit cell | the smallest repeating unit of the lattice |
X-RAY diffraction | occurs when beams of light are scattered from a regular array of points in which spacing between the components are comparable with the wavelength of the light -used to determine the structures of crystalline solids |
ionic solids | ions at the points of the lattice that describes the structure of the solid (NaCl) |
molecular solids | has discrete covalently bonded molecules at each of its lattice points (sucrose, ice) |
atomic solids | has atoms at the lattice points that describe the structure of the solid |
alloy | a substance that contains a mixture of elements and has metallic properties |
substitutional alloy | some of the host metal atoms are replaced by other metal atoms of the same size (brass) |
intersititial alloy | formed when some of the interstices (holes) in the closet packed metal structure are occupied by small atoms (steel) |
silica | -fundamental silicon-oxygen compound -SiO2 |
silicates | -found in most rocks, soils, and clays -interconnected SiO4 Tetrahedra -contain silicon-oxygen anions -salts containing metal cations and polyatomic silicon-oxygen anions |
glass | -amorphous solid -results when silica is heated above its melting point (about 1600'C) and cooled rapidly -homogeneous noncrystalline "frozen solution" |
ceramic | -typically made from clays (which contain silicates) and hardened by firing at high temperatures -nonmetallic materials that are strong, brittle, and resistant to heat and attack by chemicals -heterogeneous noncrystalline "frozen solution" |
semiconductor | -a material which has electrical conductivity between that of a conductor such as copper and an insulator such as glass. -the conductivity increases with increasing temperature, behaviour opposite to that of a metal |
n-type semiconductor | substance whose conductivity is increased by doping it with atoms having more valence e- than the atoms in the host crystal -extra e- close in energy to conduction bands and are easily excited into these levels where they can conduct an electrical curren |
p-type semiconductor | -semiconductor doped with atoms having fewer valence e- than the atoms of the host crystal -so named because the positive holes can be viewed as the charge carriers |
p-n junction | a small # of e- migrate from the n region into the p region, where there are vacancies in the low-energy molecular orbitals -effect is to place - on the p region (since it now has surplus e-) and + on the n region (since it has lost e-s, leaving holes) |
evaporation or vaporization | molecules of a liquid can escape the liquids surface and form a gas endothermic because energy is required to overcome the relatively strong IMF in the liquid |
heat of vaporization | the energy required to vaporize 1 mole of a liquid at a pressure of 1 atm |
vapor | substance that is liquid at room temperature (25'C and 1 atm) but evaporated |
condensation | the process by which vapor molecules re-form a liquid |
equilibrium | at this point no further net change occurs in the amount of liquid or vapor because the two opposite forces exactly balance each other |
vapor pressure | the pressure of the vapor present at equilibrium -increases significantly with temperature -favors weak IMF |
volatile | -liquids with high vapor pressures -they evaporate rapidly from an open dish -favor weak IMF (bigger drop - particles able to escape at room temp) |
sublimation | the process by which a solid goes directly to the gaseous state without passing through the liquid state -dry ice (solid carbon dioxide) |
heating curve | a plot of temperature versus time for a process where energy is added at a constant rate |
heat of fusion | the enthalpy change that occurs at the melting point when a solid melts |
normal melting point | the temperature at which the solid and liquid states have the same vapor pressure under conditions where the total pressure is 1 atm |
normal boiling point | the temperature at which the vapor pressure of the liquid is exactly 1 atm -favors larges e- cloud -> strongest LDF |
supercooled | -water cooled below 0'C at 1 atm & remain liquid - as it is cooled the water may not achieve the degree of organization necessary to form ice at 0'C -At some point correct ordering occurs & ice forms, release energy - bring temp to mp |
superheated | -raised to temperatures above its boiling point -occur because bubble formation in the interior of the liquid requires that many high-energy -vapor pressure is greater than the atm |
bumping | superheated liquid -once a bubble does form, since its internal pressure is greater than that of the atm, it can burst before rising to the surface, blowing the surrounding liquid out of the container |
phase diagram | way of representing the phases of a substance as a function of temperature and pressure -describes conditions and events in a closed system -Water - negative slope (liquid more compact than solid) |
closed system | no material can escape into the surroundings and no air is present |
triple point | solid, liquid water have identical vapor pressures |
critical temperature | the temp above which the vapor cannot be liquefied no matter what pressure is applied |
critical pressure | the pressure required to produce liquefication at the critical temperature |
critical point | critical temp and critical point |
increase rate of evaporation | 1. increase surface area 2. increase temperature 3. increase wind currents 4. lower pressure -a greater fraction of molecules can escape - Maxwell-Boltzmann Distribution |
dynamic equilibrium | rates of opposing reactions are equal (evaporation & condensation) |
evaporation v boiling | -phases changes (l -> g) -endothermic (absorb heat to break IMF) -boiling has bubbles -evaporation occurs @ the surface/boiling occurs throughout -evaporation, only a few particles have sufficient KE to vaporize; whereas with boiling most of the parti |
to boil | reduce pressure in surrounding heat it |
gas | if something is gas at room temp |
corner atom | shared 8 ways |
center of face | shared 2 ways |
center of edge | shared 4 ways |
interior of atom | shared 1 way |
freezing point depression | addition of non-volatile solute LOWERS the freezing point of the solvent (harder) -small ponds freeze easier than oceans // dissolved ions have lower freezing point |
Created by:
sbhati
Popular Chemistry sets