-
The rows are called
PERIODS
-
Elements in the same group in ------ size as you go down
increase
-
elements --------- in size as you go across a period
decrease
-
Ionization energies decreases
as you proceed down in a group;
-
ionization energies increases as you
go across a period.
-
The first three ionization energies of beryllium, you can identify the element from
the huge jump beween the core and valence electrons. (1 question on exam) The core ones take ALOT more energy to get rid of
-
Electron affinities
is energy change-gaining of electron by a gaseous atom
More negative- morelikely to gain electron!
-
amphoteric
can be either an acid or a base
-
the columns are called
GROUPS.
-
Pauli Exclusion Principle:
No two electronsin an atom can have the same four quantumNumbers!
-
n
- principal
- positive intergers (1,2,3)
- Orbital energy (size)
-
l
- angular momentum
- integers from 0 to n-1
- orbital shape (The l values 0, 1, 2, and 3 correspond to s, p, d, and f orbitals, respectively.)
-
ml
- magnetic
- intergers from -l to 0 to +l
- orbital orientation
-
ms
- spin
- +1/2 or -1/2
- direction of e- spin
-
Higher nuclear charge --------- orbital energy
lowers orbital energy (stabilizes the system) by increasing nucleus-electron attractions.
-
An additional electron in the same orbital -------- the orbital energy
additional electron in the same orbital raises the orbital energy through electron-electron repulsions.
-
Inner electrons shield outer electrons ---------- effectively than electrons in the same sublevel.
Inner electrons shield outer electrons more effectively than do electrons in the same sublevel.
-
The Effect of Electron Repulsions (Shielding)
Additional electron(s) in the same orbital
Additional electrons in inner orbitals
-
Electrons in a 2s orbital --------------- in a 2p orbital.
can penetrate toward the nucleus better than an electron
-
2s orbitals are less shielded by electrons and the orbital is therefore
more stable.
-
Order of sublevel energies
s<p<d<f
-
Aufbau Principle
Electron Configuration is built up byprogressively adding electrons. As they are added, they assume theirmost stable configurations.
-
Hund’s Rule
Every orbital is partially filled before it is doubly filled.
-
Inner (core) electrons
are those seen in the previous noble gas and any completed transition series.
-
Outer electrons are those
in the highest energy level of n value.
-
Valence electrons are those
- involved in forming compounds.
- Of the main group the valence = outer electrons.
- Of the transition elements we count the ns and (n-1)d as valence electrons because they participate in bonding.c.
- Of the lanthanides the valence electrons are ns and (n-2)f.
-
Exceptions, 1/2 filled S sometimes
Cr and Cu
-
Atomic size trend
increases left and down Francium is the biggest
-
Ionization Energy
increases up and right
-
electron affinity
increases up and right
-
Metallic behavior
increases left and down
-
Cations: Ions get
smaller across period and smaller than original atoms(Lose electrons!)
-
Anions:
Ions also get smaller across period and larger thanoriginal atoms and much largerthan cations!(Gain electrons!)
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