Chapter 3 Flashcards
the quantization of the
energy levels in Bohr’s
model can be explained
by
the wavelike behavior
of the electrons
The wavelike behavior of
electrons was confirmed
experimentally by the
double slit experiment
An orbital is
a region where an
electron is most probable to
reside.
An orbital is defined by
4 quantum numbers
What are the 4 quantum numbers
n, l, ml, ms
What is n
The principal quantum number n tells you the energy level of an electron
- If an electron transitions to a higher
energy level (n)… - If an electron transitions to a lower
energy level….
- energy is absorbed
in the form of a photon. - energy is released in the
form of a photon.
l specifies
the shape of the orbital
(0…n-1)
l = 0 corresponds
l = 1 corresponds
l = 2 corresponds
l = 3 corresponds
to s orbitals (sphere)
to p orbitals (dumbells)
to d orbitals
to f orbitals
A radial node is
a value where the odds of finding an electron is 0
What is ml
specifies the spatial
orientation of a orbital.
(-l…l)
The number of
possible orbitals in the same
subshell is
2l + 1.
Ms is
Spin quantum number : its the direction of the quantum “spinning”
of the electron
(+1/2, -1/2)
Electron configuration of ions
Main group elements:
the electrons that were added last are
the first electrons removed
Electron configuration of ions
Transition metals:
The highest ns electrons are lost first, then the (n – 1)d or (n – 2)f electrons are removed.
The electrons occupying the outermost shell orbital(s) are
valence electrons
those occupying the inner shell orbitals are called
core electrons
Electrons experience two conflicting
forces:
- Attraction to the nucleus
- Repulsion by other electron
The repulsion by other electrons is
called
shielding
Atoms and ions that have the same electronic configuration are said to be
isoelectronic
The size of an atom can be defined by its
Covalent Radius
More shielding means
the outer electrons are less tightly held by the nucleus, so the atom becomes bigger
Fewer shields mean
the outer electrons are held tighter by the nucleus, so the atom becomes smaller
Zeff =
= Z – shielding
the atomic size
- increases down a group: there are more core electrons blocking the nucleus’s pull
- decreases across a period: the nucleus pulls more strongly on the outer electrons, without much extra shielding
For atoms or ions that are isoelectronic the size is determined by
the number of protons
determines the size (more protons = smaller radius)
The energy required to remove the most loosely bound electron from a gaseous atom in its ground state is called
its first ionization energy (IE1)
The energy required to remove the second most loosely bound electron is
called
the second ionization energy (IE2)
Ionization energy:
- decreases down a
group - increases across a
period
Ionization energy: Deviation #1:
IE1 decreases when l
increases
Ionization energy: Deviation #2:
IE1 decreases when a
subshell becomes more
than one-half filled
The electron affinity (EA) is the
energy change for the process of adding an electron to a gaseous atom to form an anion
EAs tend to become
more negative across a period (with increasing Zeff)
EA Deviation #1:
group 2 (2A)
High positive energy
EA Deviation #2:
group 15 (5A)
low negative energy
EA Deviation #3:
noble gases
positive energy
