Chapters 7 and 8 Flashcards
The quantum numbers resulted from the…
Pauli exclusion principal (two electrons must have opposite spins if they occupy the same orbital)
Nuclear charge is based on the fact that….
electrons are both attracted to the nucleus and repelled by other electrons
Z eff = ____ - _____
Z (atomic #) - S (shielding/# of core electrons)
Effective nuclear charge is the net charge experienced by….
a particular electron in an atom resulting from a balance of the attractive forces of the nucleus and the repulsive forces of other electrons
Z eff is the charge experienced by the _____ electrons
outermost
High Z eff vs lower Z eff
The higher effective nuclear charge has a smaller atomic radius, a higher IE, and a higher electronegativity (periodic trends)
In the hydrogen atom 2s and 2p subshells have the ____ energy, but in atoms with more than two electrons the energies are ____
same different
States that lower energy orbitals fill first (predicts arrangement of electrons)
Aufbau Principal
Degenerate orbitals (those of the same energy) are filled with electrons until all are half filled before the pairing up of electrons can occur
Hund’s Rule
What is the basis of the Hund’s rule?
It results in the most stable arrangement of the electrons
When calculating effective nuclear charge (slaters law) it is best to write the electron configuration first and then….
group it together by increasing n
4f block of the periodic table
lanthanides
5f block of the periodic table
actinides
Exceptions when writing electron configurations occure when…
you get to d4 and d9 electron configurations
For example:
4s^2 3d^4 becomes 4s^1 3d^5
4s^2 3d^9 becomes 4s^1 3d^10
To form a cation, the highest n electron is removed first for example…
Iron (Ar)3d^6 4s^2 becomes Iron (Ar) 3d^6 + 2e-
How do we know the configurations of ions?
By their magnetic properties
Paramagnetic
has unpaired electrons (attracred to a magnetic field)
Diamagnetic
has all paired electrons (not attracted to a metal field)
Ferromagnitism
when the spins of unpaired electrons in a cluster of atoms/ions align themselves in the same direction even without a magnetic field
Orbital energies_____as Z* increase
drop
distance betweeen two nuclei
bond distance (half of this equals the covalent radius, which is usually in picometers)
Ionization energy is always a _____ value
positive
Ionization energy is….
the energy required to remoced an electron from an atom in the gaseous phase
The _____ to the nucleus an electron is, the higher the ionization energy
closer
Electron affinity is….
the change in energy (in kJ/mole) of a neutral atom (in the gaseous phase) when an electron is added to the atom to form a negative ion
Noble gase have _____ affinity for electrons
no
EA (ΔU) is the energy released when an electron attached to a gas-phase atom to form an anion
Compared to EA, ΔU…
Is equal in magnetude, but opposite in sign
EA= -ΔU
Anion>Atom>Cation
Why?
Smaller Cation:
Same amount of attractive forces from protons are exerted over less electrons, so the electrons are drawn closer to the nucleus
Larger Anion:
Increased electron-electron repulsion (more electrons than protons)