ch 2: water and carbon Flashcards
proton charge and mass
positive and 1 amu
neutron charge and mass
neutral and 1amu
electron charge and mass
negative and no mass
mass number
number of protons and neutrons
atomic number
number of protons
isotopes
form of an element that differs in # of neutrons
covalent bonds
two atoms share one or more pairs of electrons
nonpolar covalent bond
equally shared electrons
polar covalent bonds
uneven sharing of electrons
ions
carry full electric charge, either cation or anion
ionic bonds
electrons are completely transferred from one atom to the other and gives both atoms a full valence shell
solvent
agent for dissolving
solute
substance that is dissolved in a liquid
is water a solute or solvent
solvent
hydrogen bonds
attraction between hydrogen with a partial positive charge and another atom with a negative charge
what do hydrogen bonds form between?
water molecules and polar solutes
what compounds are hydrophilic
polar compounds containing partially or fully charged atoms
what kind of compounds are hydrophobic?
nonpolar
van der Waals
weak electrical attraction between two nonpolar molecules of parts of a molecule that have been brought together
are van der waals hydrophobic or hydrophilic?
hydrophobic
cohesion
stay together due to hydrogen bonds
example of cohesion
water molecules at the surface form hydrogen bonds with nearby water molecules and resist the upward pull of adhesion
adhesion
attractions between unlike molecules
what surfaces does adhesion occur between?
liquid and solid surface
example of adhesion
water adheres to surfaces that have polar or charged components
surface tension
cohesive forces caused by attraction between the molecules at the surface of a liquid
what type of force does water resist?
any forces that increases its surface area
what causes the elastic membrane of water to be stronger than other liquids?
hydrogen bonds
is water denser as a liquid or solid?
liquid because there are more molecules in water as a liquid than solid
specific heat
amount of energy required to raise the temperature of 1 gram of a substance by 1 degree celsius
does water have a high specific heat?
yes, because when a source of energy hits it, hydrogen bonds must be broken before heat can be transferred
heat of vaporization
energy required to change 1 gram of water from liquid to gas
why does water lose heat?
because it absorbs a lot of energy to evaporate
acids
gives up protons or accepts electrons during a chemical reaction or release hydrogen ions when dissolved
bases
gets protons or gives up electrons during a chemical reaction or accepts hydrogen ions when dissolved in water
buffers
compounds that minimize changes in pH because they reduce the impact of adding acids or bases on the overall pH of a solution
are buffers usually acids or bases?
weak acids
why are buffers important?
to maintain homostasis
polymers
long chains of monomers joined by covalent bonds
condensation reaction
joins monomers together to build a polymer
- brings energy in
hydrolysis reaction
breaks polymers apart into constituent monomers
- releases energy