Chapter 1 Flashcards
the region where electrons reside is the
extranuclear space
shells define the probability of … in various regions of space relative to the …
finding an electron; nucleus
the energy of electrons in the shells is …, which means that only specific values of energy are possible,r ather than a continuum of values
quantized
delocalization: the spreading of electron density over a larger …
volume of space
each shell can contain up to … electrons
2n^2 (n is number of shell)
electrons in the first shell are nearest to the positively charged nucleus and are held most strongly by it; these electrons are
lowest in energy
orbital: region of space that can hold … electrons and has a specific quantized energy
two
orthogonal: having no net
overlap
the electron configuration of an atom is a description of the … its electrons occupy
orbitals
according to the pauli exclusion principle, for two electrons in the same orbital, their spins must be …
paired
electrons have a quantum mechanical property referred to as spin. they have magnetic north and south poles. two electrons with opposite spins are said to have
paired spins
orbitals of equal energy are called
degenerate
the reason hund’s rule stands (electrons fill orbitals individually before doubly) is because of
electron-electron repulsion
hund’s rule also states that the spins of the single electrons in the degenerate orbitals should be
aligned
unstable structures possess energy waiting to be released. when a structure is higher in energy, the more energy it has
stored
all of nature seeks its … energy state; when electrons are rearranged back to their ground state, energy is …
lowest; released
the energy it takes to remove an electron from an atom or a molecule is called the …
ionization potential
ionization potential … across a period and … a group
across; up
an atom that gains electrons becomes an … and an atom that loses electrons becomes a ..
anion; cation
when atoms are held together primarily by …, we say that an ionic interaction exists between them
attraction of oppositely charged ions
Electronegativity increases as … increases, and does so … a period and … a group
Zeff; across; up
the energy released upon addition of an electron is called the …, which becomes more favorable as you move from … to … in a row of the periodic table
electron affinity; left; right
because the electronegativity of an atom reflects its tendency to hold on to and to acquire electrons, the phenomenon arises from a combination of … and …
ionization potentials; electron affinities
the attraction between ions is what permits ionic salts to form a strong … and gives them a high ..
crystal lattice; melting point
according to the lewis model, a pair of electrons in a covalent bond functions in two ways simultaneously: it is shared by two atoms and at the same time fills the … of each
outer shell
bond dissociation enthalpy is the energy that would have to be absorbed to
break a bond
when bonds are formed by the sharing of two electrons between adjacent atoms, the system becomes more stable because the … of the electrons is stablilized relative to two separate atoms. the wave that represents the electrons in a bond is partially concentrated in the space …, leading to … between them. in contrast, they are attracted to each … and shield the … between the two nuclei
wave character; between the nuclei; repulsion; nucleus; repulsion
the lowering of the energy of the wave character of the electrons along with their added attraction to each nucleus is balanced with the … between the … and the …. This balance results in an optimum … called the …
repulsion; nuclei; electrons; internuclear distance; bond length
the distance between nuclei participating in a chemical bond is called the
bond length
a good way to distinguish covalent bonds from ionic attraction is the fact that covalent bonds have defined … and … resulting from the … of electrons
geometries; connectivities; sharing
the polarity in the bond increases with increasing … between the bonded atoms
difference in electronegativity
nonpolar covalent is less than ..
polar covalent is less than/equal to … and greater than/equal to …
ionic is greater than …
0.5; 1.9; 0.5; 1.9
electronegativity varies somewhat depending on the …. and … state of an atom
environment; oxidation
in particular, carbon in compounds is not atomic carbon, and it often behaves as if its electronegativity is … than that shown
greater
the polarity of a covalent bond is measured by a vector quantity called a …, defined as the product of the …, e, on one of its atoms times the …, d, separating the two atoms
bond dipole; charge; distance
the charge on an atom in a molecule/polyatomic ion is called its
formal charge
formal charge = number of … - (all … electrons + 1/2 all … electrons)
valence e-; unshared; shared
when an atom possessing an octet of electrons has one bond more than its neutral state, the atom is … charged; when it has one bond less than its neutral form, it is … charged
positively; negatively
for group 3A elements, their valence shells are only … filled. trivalent compounds of boron and aluminum exhibit a high … with compounds that have extra …, enabling them to fill their octets
these elements don’t have 8 electrons after bonding
partially; reactivity; electrons
dative/coordinate covalent bonds: where the two electrons come from only a … or … while the other involved in that bond does not contribute any electrons
single group; atom
functional groups allow us to divide organic compounds into classes, and exhibit characteristic …
chemical reactions
unshared pairs of electrons are generally …. in a condensed structural formula
not shown