Questions and Answers
What is band theory?
Connected to MO theory, it describes a continuum of overlapping orbitals, where the lowest energy orbitals have no nodes between neighboring atoms, and the highest energy orbitals have nodes between every pair of neighbors. The energy separation between neighboring orbitals approaches zero, creating a near-continuous energy spectrum.
What is the s band in band theory?
Forms between s orbitals.
What is the p band in band theory?
Forms between p orbitals.
How do conductors relate to band theory?
Signup and view all the answers
What characterizes insulators in band theory?
Signup and view all the answers
Which types of semiconductors are mentioned?
Signup and view all the answers
What is ionization energy?
Signup and view all the answers
What is the periodic trend of ionization energy?
Signup and view all the answers
Why is a half filled subshell so stable?
Signup and view all the answers
What is exchange interaction?
Signup and view all the answers
What is pairing energy?
Signup and view all the answers
Is it easier to ionize high energy or low energy electrons?
Signup and view all the answers
What happens when a 3d series metal is ionized?
Signup and view all the answers
What is lanthanide contraction?
Signup and view all the answers
What are lanthanides?
Signup and view all the answers
What do Slater's rules tell us?
Signup and view all the answers
What is shielding?
Signup and view all the answers
What is penetration in atomic orbitals?
Signup and view all the answers
What is electron affinity?
Signup and view all the answers
What does electronegativity measure?
Signup and view all the answers
What is polarizability?
Signup and view all the answers
Why do we use the hydrogen system approximation?
Signup and view all the answers
What is the formula for the energy of a hydrogen orbital?
Signup and view all the answers
In which units can energy be expressed?
Signup and view all the answers
What does quantum number N represent?
Signup and view all the answers
What does quantum number L represent?
Signup and view all the answers
What does quantum number Ml represent?
Signup and view all the answers
What does quantum number Ms represent?
Signup and view all the answers
What is radial wavefunction?
Signup and view all the answers
What is a radial distribution function?
Signup and view all the answers
What is the Bohr radius?
Signup and view all the answers
What orbitals correspond to l=0 through l=4?
Signup and view all the answers
What is the building up principle/Hund's rule?
Signup and view all the answers
What is the Pauli exclusion principle?
Signup and view all the answers
What does VSEPR stand for?
Signup and view all the answers
What is the relative repulsion strengths in VSEPR?
Signup and view all the answers
What is valence bond theory?
Signup and view all the answers
How is hybridization used in valence bond theory?
Signup and view all the answers
What is the effect of a lone pair on geometry?
Signup and view all the answers
What is molecular orbital theory?
Signup and view all the answers
What are MO theory assumptions?
Signup and view all the answers
What is orbital approximation?
Signup and view all the answers
What is a linear combination of atomic orbitals?
Signup and view all the answers
What occurs in H2 and H2-like molecules?
Signup and view all the answers
What is the energy contributing in Li2 through N2?
Signup and view all the answers
Why can't Ne2 exist?
Signup and view all the answers
What is H-X interaction?
Signup and view all the answers
What is X-Y interaction?
Signup and view all the answers
What are the relative energies of molecular orbitals?
Signup and view all the answers
What is a polyatomic MO?
Signup and view all the answers
What is LCAO notation?
Signup and view all the answers
What are LCAO energies?
Signup and view all the answers
What is bond order?
Signup and view all the answers
How to calculate bond order?
Signup and view all the answers
How to assign bonding character in bonding orbitals?
Signup and view all the answers
How to assign bonding character in nonbonding orbitals?
Signup and view all the answers
How to assign bonding character in antibonding orbitals?
Signup and view all the answers
What are HOMO interactions?
Signup and view all the answers
What are LUMO interactions?
Signup and view all the answers
Why are HOMO/LUMO important?
Signup and view all the answers
What is paramagnetism?
Signup and view all the answers
What is metallic bonding?
Signup and view all the answers
What is ionic bonding?
Signup and view all the answers
What is a lattice in crystallography?
Signup and view all the answers
What is a unit cell?
Signup and view all the answers
What are the 7 types of crystal systems?
Signup and view all the answers
What is a primitive unit cell?
Signup and view all the answers
What is body-centered structure?
Signup and view all the answers
What is face-centered structure?
Signup and view all the answers
What is close packed structure?
Signup and view all the answers
What is coordination number?
Signup and view all the answers
What is cubic close packed?
Signup and view all the answers
What is face-centered cubic structure?
Signup and view all the answers
What is a hole in crystallography?
Signup and view all the answers
What is polymorphism?
Signup and view all the answers
What is an alloy?
Signup and view all the answers
What is a substitutional solid solution?
Signup and view all the answers
What is an interstitial solid solution?
Signup and view all the answers
What is lattice enthalpy?
Signup and view all the answers
What is the Born-Haber cycle?
Signup and view all the answers
What is a van der Waals interaction?
Signup and view all the answers
What is a non-stoichiometric compound?
Signup and view all the answers
What is a conductor?
Signup and view all the answers
What is a semiconductor?
Signup and view all the answers
What is an insulator?
Signup and view all the answers
What is a superconductor?
Signup and view all the answers
What is a band in solid-state physics?
Signup and view all the answers
What is a band gap?
Signup and view all the answers
What is an s/p band?
Signup and view all the answers
What is the fermi level?
Signup and view all the answers
What are the parameters for a substitutional solid solution?
Signup and view all the answers
What are the parameters for an interstitial solid solution?
Signup and view all the answers
What is the most stabilizing influence on a solid?
Signup and view all the answers
What effect does high lattice enthalpy have on solid stability?
Signup and view all the answers
What effect does low lattice enthalpy have on solid stability?
Signup and view all the answers
What is the Born-Mayer equation?
Signup and view all the answers
Why does solubility depend on lattice enthalpy?
Signup and view all the answers
What is solvent leveling?
Signup and view all the answers
Study Notes
Ionization Energy
- Energy required to remove the least tightly bound electron from a neutral atom in the gas phase.
- Periodic trend shows that ionization energy is highest at the top right of the periodic table, where smaller atoms have tighter electron hold.
Stability of Half-Filled Subshells
- Half-filled subshells maximize stabilizing interactions and minimize destabilizing electron interactions.
Electron Interaction Concepts
- Exchange interaction causes stabilizing effects from electrons pairing in degenerate orbitals with parallel spins.
- Pairing energy is a destabilizing factor, associated with electron-electron repulsion in filled orbitals.
Ionization of Electrons
- High energy electrons are easier to ionize; they require less energy input due to their initial higher energy state.
- The first electron ionized from a 3d series metal comes from the 4s orbital.
Lanthanides and Atomic Properties
- Lanthanide contraction refers to the reduction in atomic radius across the lanthanide series, contrary to general periodic trends.
- Lanthanides (elements 57-71) demonstrate the first appearance of f orbitals, which poorly shield additional electrons increasing effective nuclear charge (Zeff).
Effective Nuclear Charge and Shielding
- Slater's rules determine Zeff using the formula: Zeff = Z - sigma, where sigma accounts for shielding electrons.
- Shielding is the reduction in nuclear attraction due to inner electrons, while penetration describes how higher energy electrons can occupy lower energy shells.
Electron Affinity and Electronegativity
- Electron affinity measures the energy difference between a neutral gaseous atom and its corresponding anion, with a more positive value indicating greater stability.
- Electronegativity is the atom's ability to attract electrons in a compound, with fluorine being the most electronegative element.
Quantum Mechanics and Orbitals
- Quantum numbers describe various electron properties:
- Principal quantum number (N) defines energy and size.
- Angular momentum quantum number (L) determines the shape of orbitals.
- Magnetic quantum number (Ml) indicates orientation of the orbital.
- Spin magnetic quantum number (Ms) describes electron spin.
- Radial wavefunctions define orbitals, while radial distribution functions indicate electron probability at varied distances from the nucleus.
Molecular Structure Theories
- VSEPR theory predicts molecular geometries based on minimizing electron pair repulsions.
- Valence bond theory explains bonding via atomic orbital overlaps, with hybridization accounting for equivalent bonds exceeding valence orbitals.
- Molecular orbital (MO) theory applies to polyatomic molecules, treating electrons as delocalized within molecular orbitals.
Bonding Characteristics
- Bond order reflects overall bond strength, calculated using the formula (bonding - antibonding) / 2.
- Nonbonding, bonding, and antibonding orbitals differ in energy relative to atomic orbitals.
Conductivity and Band Theory
- Conductors have partially filled bands allowing easy electron promotion, while insulators feature filled bands with significant energy gaps hindering electron transitions.
- Band theory addresses overlapping atomic orbitals, yielding a continuous energy spectrum affecting conductivity based on band filling and electron mobility.
Crystal Structures and Solutions
- Crystals are defined by their lattice and unit cell structures, with various types including body-centered, face-centered, and primitive unit cells.
- Solid solutions form when different metals substitute or occupy interstitial sites within a crystal lattice, influenced by atomic radii and crystal structure compatibility.
Lattice Properties and Enthalpy
- Lattice enthalpy indicates the strength of ionic solids and is critical in determining solubility.
- High lattice enthalpy leads to increased stability in solids, while low lattice enthalpy indicates instability.
Summary of Types
- Distinctions among conductors, semiconductors, and insulators based on their electronic properties.
- Semiconductors can be intrinsic or extrinsic (n-type, p-type), with varying conductivity behaviors influenced by temperature changes.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on ionization energy and electron interactions in atomic structures. This quiz covers concepts such as the stability of half-filled subshells and the ionization of electrons, particularly in lanthanides and transition metals. Evaluate your understanding of periodic trends and electron behavior.