mathematical probabilities of finding electrons in space
S orbitals are __. P orbitals are __.
spheres
dumbbell
The further away from the nucleus that you go, what?
Explain mass of atoms.
Explain what electrons do.
the less likely you are to find an electron
the mass of atoms is confined to the nucleus
find each other first
If we take two s orbitals and combine them, what do we get?
a bonding MO
What does plus and minus pertain to?
the orbitals
plus is bonding
minus is antibonding
What is between two nuclei?
positive electron density
When you combine two atomic orbitals, you get __. Explain that.
two bonding orbitals
one used, one not
one bonding, the other anti
Which has higher energy, bonding or antibonding?
antibonding
Orbitals house how many electrons.
two
Single bond equals ___.
A double bond equals ___.
sigma
sigma and pi
The closer the atoms get to each other, the __. When they reach a __, they achieve a __.
If you supply enough energy, you can do what?
move electrons or promote to antibonding
Even though you expend energy raising electrons, what?
you get it back by forming bonds
What do all p orbitals have? What will one do?
a + and - lobe with a node in the middle.
the + will expand at the expense of the -
Rotation occurs in what? What is it called?
in single bonds
particular conformations
Sigma bonds are __
head on overlap of two hybrid orbitals
Pi bonds are made up of __.
They must be __ to each other.
They are __
exposed; a top part and a bottom part
parallel
not twice as strong as single bonds; they are considerably weaker
No __ around a double bond.
free roation
If you rotate a double bond, what do you do?
you break the double bond and hcange the properties
What's left after sigma bonds are __.
pi bonds left over
True or False:
saturated atoms in a ring are flat
false
not flat
wedges indicate __
the structure is coming at you
dashes indicate
the structure is going away from us
The farther away from the nucleus you get, what?
the lower the electron density
Destructive overlap of waves causes __.
antibonding MO
opposite waves separated by a function
__ lies between the nuclei.
A bond may be formed by __
The __ is lower in energy than the original atomic orbitals
The __ is higher in energy than the atomic orbitals
electron density
s-s, s-p, p-p
bonding MO
antibonding MO
P orbitals occupy the __.
Cartesian coordinates
P orbitals are __ from each other, but we don't use that angle. WE only use __.
90
120
109
180
The excited state does what?
bump electrons to higher energy orbitals
Ethane is composed of __ bonded by the overlap of their __.
There is __ along single bonds.
two methyl groups
sp3 hybrid orbital
free rotation
A double bond (two pairs of shared electrons) consists of __>
a sigma bond and a pi bond
A __ (three pairs of shared electrons) consists of __.
triple bond
sigma bond
two pi bonds
True or False:
Double bonds cannot rotate.
Explain whether true or false.
True
it'll break the pi bond
Compounds that differ in how their substitutents are arranged around the double bond can be __ and __.
isolated
separated
Isomerism:
- What are they?
molecules that have the same molecular formula but differ in the arrangement of their atoms are called isomers
Constitutional isomers
differ in their bonding sequence
Stereoisomers
differ only in the arrangement of the atoms in space
Constitutional isomers have the __, but the atoms are __.
They have __.
The number of isomers increases rapidly as the __ increases.
same chemical formula
connected in a different order
different properties
number of carbon atoms
Stereoisomers
are compounds with the atoms bonded in the same order, but their atoms have different orientations in space
__ are examples of geometric stereoisomers; they occur when there is a __ in the compound.
cis and trans
double bond
Since there is no free rotation along the __, the groups on these carbons can __.
carbon carbon double bond
point to different places in space
The best bonding orbitals are those that __.
provide the greatest electron density in the bonding region while keeping the three pairs of bonding electrons as far apart as possible
Bond angles cant be explained with simple __.
__ is used to explain the molecular shape of molecules.
__ are lower in energy because __ are farther apart.
s and p orbitals
valence-shell electron pair repulsion theory (VSEPR)
