Exam Two Flashcards
electronegativity
caused by an unequal sharing of electrons
hydrogen bonds
form when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom
heat
a measure of the total amount of kinetic energy due to molecular energy
transfer of heat
normally occurs from a high temp. object to a low temp. object
kinetic energy
the energy of motion
specific heat
amount of heat that must be absorbed or lost for 1g of that substance to change its temp. by 1 degree celsius
heat of vaporization
amount of heat that must be absorbed for 1g of that substance to be converted to gas
cohesion
hydrogen bonds hold water together
adhesion
attraction between different substances
surface tension
a measure of how hard it is to break the surface of a liquid
solvent
the dissolving agent of a solution
solute
the substance that is dissolved
solution
a liquid that is a homogeneous mixture of substances
aqueous solution
one in which water is the solvent
hydration shell
when an ionic compound is dissolved in water, each ion is surrounded by a sphere of water molecules
acidic
high H+ concentration (0-7)
basic
low H+ concentration (7-14)
evaporation
liquid to gas
transpiration
when water molecules evaporate off of plants
evapotranspiration
evaporation + transpiration
condensation
gas to liquid
precipitation
discharge of water in either liquid or solid state
groundwater
water that fills empty spaces and cracks in the soil
aquifer
underground soil or rock through which water easily moves
porosity
amount of spaces in an aquifer
permeability
a measure of how well spaces are connected
water table
top of the water in soil
recharge
water that enters/adds to ground water (rain)
discharge
water leaving an aquifer (wells, lakes, rivers)
coagulation
after screening out large objects from the water, coagulant chemicals are added to cause suspended particles to clump together
sedimentation
water moves into quiet sedimentation basins where sediments settle out
filtration
water is filtered through sand, membranes, or other materials
disinfection
chemical additives, ozone, or UV light are used for disinfection in order to eliminate specific contaminants to prevent corrosion of the distribution system or to prevent tooth decay
subsidence
lowering of ground surface due to lack of groundwater
discharge (Q)
the volume of water passing a location along a stream over some time interval
baseflow
groundwater input
storm runoff
increases to discharge above baseflow
the rising limb
the increase in discharge
the peak
maximum discharge following a rain event
magnitude of the peak
affected by the severity of the storm and the pathways of water to the stream
the recession limb
the return to baseflow conditions
lag to peak (lag time)
time between peak rainfall and peak discharge
isotopes
two atoms of an element that differ in number of neutrons but have the same number of protons
groups
elements in a vertical column that have the same number of electrons in their valence shell and thus have similar properties
periods
each horizontal row contains elements with the same number of electron shells, ordered by increasing atomic number
covalent bond
the sharing of a pair of valence electrons by two atoms, the shared electrons count as part of each atom’s valence shell
single covalent bond
sharing of one pair of valence electrons
double covalent bond
sharing of two pairs of valence electrons
electronegativity
an atom’s attraction for the electrons in a covalent bond
nonpolar covalent bond
the atoms share the electron equally
polar covalent bond
one atom is more electronegative, and the atoms do not share the electron equally
ionic bond
atoms sometimes strip electrons from their bonding partners, both atoms have charges
ionization energy
amount of energy required to remove an electron from an atom
electron affinity
amount of energy released when an electron is added to form a negative ion
