Chapter 5-Electron Configuration Flashcards
What can be used to determine electron arrangement in an atom?
set of 3 rules: aufbau principle, Pauli exclusion principle, Hund’s rule
All atoms can be described with orbitals similar to…
Hydrogen’s orbitals
electron configuration
arrangement of e’s in an atom
E’s assume the arrangement that gives the atom the _____ energy possible
lowest
ground state e configuration
most stable, lowest energy arrangement of e’s
aufbau principle
each e occupies lowest energy orbital available
aufbau diagram
shows sequence of atomic orbitals from lowest to highest energy
aufbau: all orbitals related to an energy sublevel are of…
equal energy
ex. all three 2p orbitals are of equal energy
aufbau: in a multi-e atom, the energy sublevels w/in a principal energy level have…
different energies
ex. the three 2p orbitals are of higher energy than the 2s orbital
aufbau: orbitals related to energy sublevels w/in one principal energy level can ____ orbitals related to energy sublevels w/in another principal level
overlap
ex. 4s sublevel has lower energy than 3d sublevel
e’s in orbitals are represented by ____ in _____
arrows…boxes
empty box represents
unoccupied orbital
pauli exclusion principle
max of 2 e’s can occupy a single atomic orbital, but only if they have opposite spins
by Wolfgang Pauli after observing excited atoms
max number of e’s related to each principal energy level is…
2n^2
Hund’s rule
single e’s w/ same spin must occupy each equal-energy orbital before additional e’s w/ opposite spins can occupy the same orbitals
ex. ^ ^ ^, then ^v ^ ^
ways to represent e configuration
orbital diagrams
electron configuration notation
orbital diagram
arrows in boxes
each box labeled with principal quantum # and sublevel associated w/ orbital
electron configuration notation
1s^2 2s^2…
doesn’t usually show the orbital distributions of e’s related to a sublevel
noble gas notation
shortcut e configuration w/ noble gas
has ns^2 and np^6 full
[Ne]3s^2
noble gases
elements in last column of periodic table
8 e’s in outermost orbital
stable
exceptions to Aufbau Rule
chromium: [Ar]4s1,3d5
copper: [Ar]4s1,3d10
to be more stable, draw box diagram to see (look at video)
valence e’s
e’s in outermost orbitals
OCCUPY THE S AND P OF THE SAME HIGHEST ENERGY LEVEL
what do valence e’s determine?
chemical properties of an element
why do scientists only show valence e’s in e-dot structures?
since these e’s are involved in forming chemical bonds
electron dot structure
element’s symbol w/ dots around it representing the valence e’s
who devised the electron dot structure method?
G.N. Lewis (American chemist)
Aufbau rule is also called the what?
diagonal rule
Which rule supports the box diagram?
Hund’s rule
isoletric
when atoms have same e configuration
How do you determine an atom’s charge?
write out e configuration and see if it would be easier to take in e’s or lose e’s
gain: (-) charge
lose: (+) charge
How to write e configuration of atoms with a charge
ex. Pd^(+2)
[Kr]5s2,4d8 –> [Kr]4d8
lose 2 e’s (take from outermost orbital w/ highest
energy level)
diamagnetic
paired e’s
^v ^v
paramagnetic
unpaired e’s aligned w/ a magnetic field
farromagnetic
unpaired e’s that remain aligned when no magnetic field exists
*Fe the only element
Periodic Table (where are the sublevels located?)
(look at skitch)
positive ions are ____ and negative ions are ____
metal
non metals
In which principal energy level do the different sublevels begin to overlap?
n=4
the d’s
what does each sublevel look like?
Spherical: sphere
Principal: dumbbell
Diffuse: donut shape
Fundamental: multiple
How many e’s can each sublevel hold?
s: 2
p: 6
d: 10
f: 14
