Ch. 1: Gen Chem Electronic Structure & Bonding Flashcards
atomic number
of protons in its nucleus (or the number of electrons that surround the neutral atom).
mass number
sum of atom’s protons and neutrons.
isotopes
atoms that have the same atomic number but different mass numbers.
atomic weight
average mass of the atoms in the element.
molecular weight
sum of the atomic weights of all the atoms in the molecule
atomic orbital
the volume of space around the nucleus where an electron is most likely to be found. The closer the atomic orbital is to the nucleus, the lower is its energy.
Minimum energy corresponds to _____ .
maximum stability
Degenerate orbitals have the _____ energy.
same
Electrons are assigned to orbitals (atomic or molecular) following the
(1) ____________________,
(2) ____________________, and
(3) ____________________ .
(1) Aufbau principle,
(2) Pauli exclusion principle, and
(3) Hund’s rule.
Octet rule states _______________ in order to fill its outer shell or attain an outer shell with eight electrons.
that an atom will give up, accept, or share electrons
Electronegative elements readily _____ electrons.
acquire
Electronic configuration of an atom describes ___________________ .
the atomic orbitals occupied by the atom’s electrons
A proton is (1) __________ charged hydrogen ion; a hydride ion is a
(2) ___________ charged hydrogen ion.
(1) positively
(2) negatively
A polar covalent bond is (1) _________ .
A polar covalent bond has a
(2) __________ (a positive end and a negative end), measured by a dipole moment.
(1) a covalent bond between atoms with different electronegativities
(2) dipole
formula for calculating dipole moment of a bond
the size of the charge X the distance between the charges
(1) _________ are electrons in inner shells.
(2) _________ are electrons in the outermost shell.
(1) core electrons
(2) valence electrons
formula for formal charge
of valence electrons - # of electrons the atom has to itself (all the lone-pair electrons and one-half the bonding electrons)
Lewis structures indicate _______ .
which atoms are bonded together and show lone pairs and formal charges
A (1) _________ has a positively charged carbon, a (2) _________ has a negatively charged carbon, and a (3) ______ has an unpaired electron.
(1) carbocation
(2) carbanion
(3) radical
According to _____________ , covalent bonds result when atomic orbitals combine to form molecular orbitals.
molecular orbital (MO) theory
Two atomic orbitals combine to give a
(1) ____________ and a higher energy
(2) ____________ .
(1) bonding MO
(2) antibonding MO
What do electrons in a bonding MO do? What do electrons in an antibonding MO do?
Electrons in a bonding MO assist in bonding. Electrons in an antibonding MO detract from bonding.
There is zero probability of finding an electron at a ______.
node
Sigma bonds vs. pi bonds
Sigma bonds are cylindrically symmetrical bonds. Pi bonds are formed through side-to-side overlap of parallel p orbitals.
Which one is stronger: a sigma bond or a pi bond?
A sigma bond is stronger than a pi bond.
What does carbon have to do to form 4 bonds?
Carbon has to promote an electron from an s orbital to an empty p orbital.
C, N, O, and the halogens form bonds using (1) _____ . Hybridization of C, N, or O depends on the number of pi bonds the atom forms: no pi bonds = (2) ___, one pi bond = (3) ___, and two pi bonds = (4) ___.
Exceptions are carbocations and carbon radicals, which are (5) ___ .
(1) hybrid orbitals
(2) sp3
(3) sp2
(4) sp
(5) sp2
All single bonds in organic compounds are ______ bonds.
sigma
A double bond consists of (1) ________; a triple bond consists of (2) _________.
(1) one sigma bond and one pi bond
(2) one sigma bond and two pi bonds
The greater the electron density in the region of orbital overlap, the _________ the bond.
shorter and stronger
Rank the strength of the main 3 bonds from lowest to highest.
single bond < double bond < triple bond
___________ is determined by hybridization: sp3 is tetrahedral, sp2 is trigonal planar, and sp is linear.
Molecular geometry
____________ around an atom stay as far apart as possible.
Bonding pairs and lone-pair electrons
The ____________ in the orbital used to form a bond, the shorter and stronger the bond and the larger the bond angle.
more s character
