a water molecule is polar because its hydrogen and oxygen atoms
do not share the elcetrons equally
changing the course or pathway of a chemical reaction so that it requires less activation energy
is aaccomplished by the action of catalysts on reactants
atoms are composed of
protons witha positive charge
neutrons with no charge
electrons witha negative charge
a molecule that has a partial posibive charge on one side and partial negative charge on the other side is called a
polar molecule
atoms become more stable when they form compunds because
their outer orbitals become filled when they form compunds
the term base and alkaline refer to solutions that
contain more hydroide ions than hydronium ions
polar molecules such as water have
both negative and positive poles
matter in the universe is composed of
atoms
the bond formed when two atoms share a pair of electrons is called a
covalent bond
an atom that has gained or lost electrons is called an
ion
what tend to prevent great fluctions in pH?
buffers
the eltrons of an atom
orbit the nucleus in various energy levels
the smallest particle of c arbon that can retain the chemical properties of carbon is
a carbon atom
a neutral soulution has an equal number of
hydroide and hydronium ions
what are able to heat up molecules so that they can react?
enzymes
a soulution wiht a pH of 11 is
alkaline
water is a polar molecule because
different parts of the molecule have lsightly different charges
a single organism may contain
thousands of different enzymes, each on specific to a different chemical reacton
atoms that have gained energy
have electrons that move to higher energy levels
what charcteristics of fwater is a result of hydrogen bonding?
cohesive strength
capillarity
adhesive strength
which of the follwing states of matter contain particles that are tightly linked together in a definite shape?
solid
because carbon has four electrons in its outer energy level,
it can react with up to four other atoms to form a covalent bonds
a substance that is composed of oonly one type of atom is called
element
acidic soulutions have a pH that is
less than 7
oxidation-reduction reactions are important in organisms because th ey
allow the passage of energy from molecule to molecule
when a molecule gains an electron it has been
reduced
the concentration of a soulution is
the amount of solute that is dossolved ina fixed amount of a solution
substances that re hccanged when they become involved in chemical reactions are calle d_______ while the new substances that are formed are called ____?
reactions, product
the loss of electroins form a molecule is called_______, while the gain of electrons by a molecule is called______
oxidation, redoction
________and_______ions form when water dissociates?
hydrogen and hydroxide
a substance that dissolves in another is called________
solute
_________is the most common solvent in cells
water
buffers are important becasue body fluids must be maintained within a relatively narrow range of ___?
pH
an acidic solution is one that has more___than______ ions
hydronium, hydroxide
the energy needeed to break existing chemical bonds during the initiation of chemical reaction is called_______
activation energy.
water is very effective at dissolving other polar substances because of its_____?