Inorganic Chemistry ACS : Study Guide Verified Questions And Answers Ionization energy ✅energy required to remove the least tightly bound electron from a neutral atom in the gas phase periodic trend of ionization energy ✅highest at top right -smaller electron=harder to remove Why is a half filled subshell so stable? ✅it serves to maximize the stabilizing interactions while minimizing the destabilizing interactions among electrons exchange interaction ✅pie, stabilizing, result of electrons pairing in degenerate orbitals with parallel spin pairing energy ✅destabilizing, coulomb interaction, pic, energy of electron -electron repulsion in a filled orbital Is it easier to ionize a high energy or low energy electrons ✅high energy electron -
already contains more energy so it requires less energy input What happens when a 3d series metal is ionized? ✅the first electron to be ionized will come from the 4s orbital, the other s electron will enter the d orbital (4s03dn+1) lanthanide contraction ✅reduction in atomic radius following the lanthanide series, contrary to the overall trend observed for the periodic table lanthanides ✅elements 57 -71, first appearance of f orbitals, f orbitals are poor at shielding so any electrons dded will have a higher Zeff, shrinking the radius Slater's rules ✅tell us what the effective nuclear charge will be, Zeff=Z -sigma, Z is the atomic number, sigma=sum of the number of electrons in a given subtle multiplied by a weighting coefficient (page 1) Shielding ✅the reduction in charge attraction between the nucleus and electrons due to electrons between the nucleus and the electron in question, it is considered the be between if it has a lower energy penetration ✅when an electron of a higher atomic orbital is found within the shell of electrons of a lower atomic number, that is to say that an electron of higher energy is found within an orbital of lower energy electron affinity ✅the difference in energy for a neutral gaseous atom, and the gaseous anion. used interchangeably with electron gain enthalpy. more positive=more stable EA with the additional electron, more positive EGE=more stable with extra electron Combination of electron affinity and ionization energy ✅electronegativity, overall measure of an atoms ability to attract electrons to itself when part of a compound, fluorine has highest electronegativity polarizability ✅an atoms ability to be distorted by an electric field, regions of a molecule can take on partial positive or partial negative charge Why do we use the hydrogen system approximation ✅systems involving multiple electrons are much more complex, and they require the use of quantum mechanics What is the formula for the energy of a hydrogen orbital ✅E=-13.6(eV)*(Z^2/n^2), h is plancks constant (background on pg 4) Energy can be expressed in... ✅Joules, wavenumber, inverse centimeters quantum number N ✅principle quantum number, defines energy and size of orbital quantum number L ✅orbital angular momentum quantum number, defines the magnitude of the orbital angular momentum, as well as the angular shape of the orbital, L can have values of 0 to n -1. quantum number Ml ✅magnetic quantum number, describes the orientation of the angular momentum, ml can have values of 0 to +/ -1 quantum number Ms ✅spin magnetic quantum number, defines intrinsic angular momentum of an electron, Ms can have values of either +1/2 or -1/2 Radial wavefunction ✅(R(r)), along with the angular wavefunction, gives us the orbitals. With a wave function it is possible to completely characterize a particle, goes to zero at infinity, produce characteristic shapes when graphed Radial distribution function ✅a plot of R^2(r)r^2, tells us probability of finding an electron at a certain distance from the nucleus, every orbital has a different radial distribution function and a node on the graph is a region of zero probability Bohr radius ✅the most probably distance to find the electron in a one proton, one electron system (52.9 pico -meters) What orbitals correspond to l=0 through l=4 ✅L=0=s, L=1=p, L=2=d, L=3=f, L=4=g Building up principle/Hund's rule ✅when degenerate orbitals are available for occupation, electrons occupy separate orbitals with parallel spin Pauli exclusion principle ✅no more than two electrons can occupy a single orbital, and to do so, their spins must be paired Descibe VSEPR ✅purpose is to predict molecular geometries, basic assumption is that regions of enhanced electron density take positions as far apart as possible in order to minimize repulsive forces. Relative repulsion strengths VSEPR ✅lone pair> multiple bonds> single bonds Valence bond theory ✅explains chemical bonding by considering the overlap of tomic orbitals, wave patterns of atomic orbitals interfere constructively to form a bond, sigma is formed when orbital overlap has cylindrical symmetry, pi bond forms when they overlap side by side af ter the formation of a sigma bond How is hybridization used in valence bond theory ✅explains bonding where the number of equivalent bonds exceeds the number of valence orbitals Effect of a lone pair on geometry? ✅it pushes strongly against all other substituent. It is the strongest force governing the shape of a molecule Molecular orbital theory ✅an improvement over valence bond theory in that the bonding description extends to all atoms in a molecule and handles polyatomic molecules, atomic orbitals combine to form molecular orbitals which are delocalized descriptions of electron distribution MO theory assumptions ✅orbital approximation, linear combinations of atomic orbitals Orbital approximation ✅the wave function describing all of the electrons of a molecule can be written as a product of the one electron avefunctions linear combination of atomic orbitals ✅the superposition of multiple atomic orbitals of same type along with weighting coefficients H2 and H2 -like molecules ✅the 1s orbitals are of equal energy so they lie at the same level of the diagram, atomic orbitals combine to form one sigma orbital which is lower in energy than one anti bonding sigma orbital which is higher in energy Li2 through N2 (period 2) ✅energy contributing to each atom is the same, 2s orbitals combine to form a bonding 1sigmag and an anti bonding sigmau, as well as a bonding 2sigmag, although that MO is mainly 2p in character. 2p combine as follows: lowest
