Bonding
1) determines how atoms come t________ to form molecules
2) they govern the ways those molecules i_______ w/ other molecules
1) determines how atoms come together to form molecules
2) they govern the ways those molecules interact w/ other molecules
Carbon
-its is t_________ (having a valence of four)
#NAME?
Two types of chemical bonds:
1) ionic
2) covalent
Ionic bonds
in which electrons are t_______ from one atom to another and the resulting ions are held together by electrostatic interactions
in which electrons are transferred from one atom to another and the resulting ions are held together by electrostatic interactions
Covalent bonds
in which electrons are s_______- between atoms
in which electrons are shared between atoms
What are the 3 quantum numbers?
n, l, ml pg.66
What does those quantum numbers describe?
size, shape, number, and orientation of an atomic o_______ on an element
size, shape, number, and orientation of an atomic orbital on an element
Principle quantum number n:
it corresponds to the e________level of a given electron in an atom and is essentially a measure of S____
-the smaller the number:
1) the c_____ the shell is to the nucleus
2) the lower its e________
-the n values go from 1 to
it corresponds to the energy level of a given electron in an atom and is essentially a measure of SIZE
-the smaller the number:
1) the closer the shell is to the nucleus
2) the lower its energy
-the n values go from 1 to 7
Azimuthal quantum number l:
-it describe the subshells s______
-it ranges from __ to n-__
-the l values: 0,1,2,3 corresponds to the _,_,_,_ subshells
-it describe the subshells shape
-it ranges from 0 to n-1
-the l values: 0,1,2,3 corresponds to the s,p,d,f subshells
How is the azimuthal quantum number (l) similar to the principle quantum number (n)?
the ______ would increase as the azimuthal quantum number increases
energy would increase as the azimuthal quantum number increases
Magnetic quantum number m1:
-it describes the o________ within each subshell
-these orbitals range from -_ to +_ for each subshell
-it basically describes the o_________
-each atomic orbital have a specific s______, which describe the p__________ of findi
#NAME?
s-orbital
s_________ and s___________, c______ around the nucleus
spherical and symmetrical, centered around the nucleus
p-orbital
-composed of t___ lobes located symmetrically about the nucleus
-contains a n____
-its a d_________ that can be positioned along these axis:
1)
2)
3)
-composed of two lobes located symmetrically about the nucleus
-contains a node
-its a dumbbell that can be positioned along these axis:
1) x-
2) y-
3) z-
Node
an area where the probability of finding an electron is z___(at the nucleus)
an area where the probability of finding an electron is zero (at the nucleus)
What are the possible values for ml when the p subshell has an l-value of 1?
ml: -1, 0, 1
d-orbital
composed of __ symmetrical lobes and contains __ nodes
composed of 4 symmetrical lobes and contains 2 nodes
Spin quantum number ms:
The values of ms are:
+1/2 and -1/2
Molecular orbitals
they form when 2 atomic orbitals combine
Bonding orbitals
Occurs when the signs of the wave functions are the same, resulting in a:
* lower-energy (more stable) bonding orbital
Occurs when the signs of the wave functions are the same, resulting in a:
* lower-energy (more stable) bonding orbital
Antibonding orbital
Occurs when the signs of the wave functions are different,
resulting in a:
*higher-energy (less stable) anti bonding orbital
sigma (?) bond
Occurs when a molecular orbital is formed by:
1)head-to-head overlap
2)tail-to-tail overlap
Pi (?) bond
-its when two p-orbitals line up in a parallel (side-by-side) fashion, their electron clouds overlap
Single bonds
-they're all sigma (?) bonds
-they accommodate 2 electrons
-they allow free rotation of atoms around the bond axis
Double bond
-its when one ? bond on top of an existing ? bond
-they don't allow free rotation of atoms around the bond axis
Triple bond
-its when there is ? bond and two ? bonds
-they don't allow free rotation of atoms around the bond axis
What happens to the bond length as more bonds are formed between atoms?
it will get shorter
TURE/FLASE: shorter bonds require more energy to break
TRUE
Which one is stronger ? or ? bonds?
-individuel ? bonds are w_____ than ? bonds
-NOTE: even though the ? bonds are weaker than ? bonds , the strength is additive, making double and triple bonds stronger overall than single bonds
-break a s______ bond requ
-individuel ? bonds are weaker than ? bonds
-NOTE: even though the ? bonds are weaker than ? bonds , the strength is additive, making double and triple bonds stronger overall than single bonds
-break a single bond requires a lot of energy
hybridization
the concept of mixing atomic orbitals into new hybrid orbitals to make all the bonds to a central atom equivalent to each other
hybrid orbitals
formed by mixing different types of orbitals
-hybrid orbitals are just the product of the porcess of hybridization that forms covalent bond.
-Hybrid orbital are completely different in shape and energy than the atomic orbitals.
sp hybridization can be determined by...?
1)attached groups
2) lone pairs
sp
-50% S
-50% P
# of attached atoms + # of lone pairs: 2
-Bond angles: 180�
-Molecular geometry: Linear
-two of its unhybridized p-orbital can be used to form a ? bond
-
How do we form a triple bond in sp?
-2 unhybridized p-orbitals will form ? bonds
-the 3rd p-orbital will combine w/ the s-orbital to form sp-orbital
sp2
-33% S
-67% P
# of attached atoms + # of lone pairs: 3
-Bond angles: 120�
-Molecular geometry: Trigonal planar
-this hybridization seen in alkenes (carbon-carbon double bond)
-one of its unhybridized p-orbital can be used to form a ? bond
-hybridized orbi
sp3
-25% S
-75% P
# of attached atoms + # of lone pairs: 4
-Bond angles: 109.5�
-Molecular geometry: Tetrahedral
Which p-orbital participate in the ? bond? why?
the 3rd p-orbital, b/c that 3rd p-orbital of each carbon is left unhybridized (which can participate in the ? bond)
What is required so resonance delocalization of electrons could take place?
conjugation
Conjugation
requires alternating single and multiple bonds b/c this pattern aligns a number of unhybridized p-orbitals down the backbone of the molecule
-it adds stability to the molecule
Bond strength is determined by the degree of orbital overlap: the greater the overlap, the greater the bond strength
A ? bond is weaker than a single bond b/c there is significantly less overlap btw the unhybridized p-orbitals of a ? bond