Chem 101 Exam 2 Full Flashcard Set (ALL DA CHUNKS)

Quantum & Atomic Theory — What is the de Broglie equation?

λ = h/p = h/(mv). It relates a particle's wavelength to its momentum.

Quantum & Atomic Theory — What does λ represent?

Wavelength.

Quantum & Atomic Theory — What does h represent?

Planck's constant.

Quantum & Atomic Theory — What does p represent?

Momentum.

Quantum & Atomic Theory — What is the Heisenberg uncertainty principle?

You cannot simultaneously know a particle's exact position and exact momentum with unlimited precision.

Quantum & Atomic Theory — What does the Schrödinger equation describe?

The behavior of electrons using quantum mechanics; its solutions give allowed electron states/orbitals.

Quantum & Atomic Theory — What is a photon?

A packet of electromagnetic energy.

Quantum & Atomic Theory — What is the equation for photon energy?

E = hν.

Quantum & Atomic Theory — What is the relationship between wavelength and frequency?

c = λν. As wavelength increases, frequency decreases.

Quantum & Atomic Theory — What happens to photon energy when frequency increases?

Photon energy increases because E = hν.

Quantum & Atomic Theory — What is a line spectrum?

A spectrum containing discrete lines at specific wavelengths/energies.

Quantum & Atomic Theory — What is a continuous spectrum?

A spectrum containing a continuous range of wavelengths.

Quantum & Atomic Theory — What is the photoelectric effect?

Emission of electrons from a material when light of sufficient frequency strikes it.

Quantum & Atomic Theory — What is threshold frequency?

The minimum frequency of light required to eject photoelectrons from a material.

Quantum & Atomic Theory — What is wave-particle duality?

Matter and electromagnetic radiation can exhibit both wave-like and particle-like behavior.

Quantum & Atomic Theory — What is quantization?

The idea that certain physical quantities can have only specific allowed values.

Quantum & Atomic Theory — What is an orbital?

A region of space described by a wavefunction where an electron is likely to be found.

Quantum & Atomic Theory — What does the principal quantum number n describe?

The main energy level/shell and general size and energy of an orbital.

Quantum & Atomic Theory — What values can n have?

Positive integers: 1, 2, 3, ...

Quantum & Atomic Theory — What does the angular momentum quantum number l describe?

The subshell/orbital shape.

Quantum & Atomic Theory — What values can l have?

0 through n−1.

Quantum & Atomic Theory — What does l = 0 mean?

s subshell.

Quantum & Atomic Theory — What does l = 1 mean?

p subshell.

Quantum & Atomic Theory — What does l = 2 mean?

d subshell.

Quantum & Atomic Theory — What does l = 3 mean?

f subshell.

Quantum & Atomic Theory — What does the magnetic quantum number ml describe?

The orientation of an orbital within a subshell.

Quantum & Atomic Theory — What values can ml have?

−l through 0 through +l.

Quantum & Atomic Theory — What does the spin quantum number ms describe?

The electron spin; it can be +1/2 or −1/2.

Quantum & Atomic Theory — How many orbitals are in an s subshell?

1 orbital.

Quantum & Atomic Theory — How many electrons can an s subshell hold?

2 electrons.

Quantum & Atomic Theory — How many orbitals are in a p subshell?

3 orbitals.

Quantum & Atomic Theory — How many electrons can a p subshell hold?

6 electrons.

Quantum & Atomic Theory — How many orbitals are in a d subshell?

5 orbitals.

Quantum & Atomic Theory — How many electrons can a d subshell hold?

10 electrons.

Quantum & Atomic Theory — How many orbitals are in an f subshell?

7 orbitals.

Quantum & Atomic Theory — How many electrons can an f subshell hold?

14 electrons.

Quantum & Atomic Theory — What is the general shape of an s orbital?

Spherical.

Quantum & Atomic Theory — What is the general shape of a p orbital?

Dumbbell-shaped; there are three orientations.

Quantum & Atomic Theory — What does degenerate mean for orbitals?

Orbitals have the same energy.

Quantum & Atomic Theory — What is the Aufbau principle?

Electrons occupy lower-energy orbitals before higher-energy orbitals.

Quantum & Atomic Theory — What is Hund's rule?

Electrons occupy degenerate orbitals singly with parallel spins before pairing.

Quantum & Atomic Theory — What is the Pauli exclusion principle?

No two electrons in an atom can have the same four quantum numbers; an orbital holds at most two electrons with opposite spins.

Quantum & Atomic Theory — What is a ground state?

The lowest-energy electron arrangement of an atom.

Quantum & Atomic Theory — What is an excited state?

An electron arrangement in which one or more electrons occupy higher-energy orbitals than in the ground state.

Quantum & Atomic Theory — What are valence electrons?

Electrons in the outermost occupied shell that are important in bonding and reactivity.

Quantum & Atomic Theory — What are core electrons?

Electrons that are not valence electrons.

Quantum & Atomic Theory — What is a condensed electron configuration?

An electron configuration written using the previous noble gas in brackets plus the remaining electrons.

Quantum & Atomic Theory — What does the periodic table help you predict about electron configurations?

Elements in the same group have related valence-electron patterns and often similar chemical behavior.

Periodic Trends — What is effective nuclear charge (Zeff)?

The net positive attraction an electron experiences from the nucleus after shielding by other electrons.

Periodic Trends — What is shielding?

Core and other electrons reduce the full nuclear attraction experienced by a valence electron.

Periodic Trends — How does atomic radius generally change across a period?

It decreases from left to right.

Periodic Trends — How does atomic radius generally change down a group?

It increases down a group.

Periodic Trends — Why does atomic radius decrease across a period?

Nuclear charge increases while electrons are added to the same general shell, increasing attraction to the nucleus.

Periodic Trends — Why does atomic radius increase down a group?

Additional occupied shells place valence electrons farther from the nucleus and increase shielding.

Periodic Trends — How do cations compare in size with their neutral atoms?

Cations are smaller than their neutral atoms.

Periodic Trends — How do anions compare in size with their neutral atoms?

Anions are larger than their neutral atoms.

Periodic Trends — What is an isoelectronic species?

Atoms or ions with the same number of electrons.

Periodic Trends — For isoelectronic ions, which ion is smaller?

The one with the greater nuclear charge (more protons).

Periodic Trends — How does first ionization energy generally change across a period?

It increases from left to right.

Periodic Trends — How does first ionization energy generally change down a group?

It decreases down a group.

Periodic Trends — Why does ionization energy generally increase across a period?

Electrons are held more strongly as effective nuclear charge increases.

Periodic Trends — Why does ionization energy generally decrease down a group?

The valence electron is farther from the nucleus and more shielded.

Periodic Trends — What is first ionization energy?

The energy required to remove the first electron from a gaseous atom.

Periodic Trends — What is electron affinity?

The energy change associated with adding an electron to a gaseous atom.

Periodic Trends — What trend should you know for electron affinity?

In general, electron affinity becomes more favorable toward the upper-right of the periodic table, with important exceptions.

Periodic Trends — What do successive ionization energies tell you?

They show the energy required to remove electrons one at a time and can reveal how many valence electrons an atom has.

Periodic Trends — What does a very large jump in successive ionization energies indicate?

The next electron is a core electron, so the number removed before the jump corresponds to the number of valence electrons.

Periodic Trends — How do transition metals differ from many main-group metals in ionic charge?

Transition metals commonly form ions with more than one possible charge.

Bonding — Why do atoms form bonds?

Bonding can lower the system's potential energy and produce more stable arrangements.

Bonding — What is an ionic bond?

Electrostatic attraction between oppositely charged ions.

Bonding — What is a covalent bond?

A bond formed by sharing electrons between atoms.

Bonding — What is electronegativity?

A measure of an atom's tendency to attract bonding electrons.

Bonding — How does electronegativity generally change across a period?

It increases from left to right.

Bonding — How does electronegativity generally change down a group?

It decreases down a group.

Bonding — Which element has the highest electronegativity?

Fluorine.

Bonding — What happens to bond polarity as electronegativity difference increases?

The bond becomes more polar.

Bonding — Which atom gets the partial negative charge in a polar bond?

The more electronegative atom.

Bonding — What does a dipole arrow indicate?

The direction of bond polarity toward the more electronegative atom.

Bonding — What is lattice energy?

The energy associated with the formation/separation of an ionic solid from its gaseous ions; larger magnitude generally corresponds to stronger ionic attraction.

Bonding — How does ionic charge affect ionic attraction?

Higher-magnitude charges generally produce stronger electrostatic attraction.

Bonding — How does ionic size affect ionic attraction?

Smaller ions generally have stronger electrostatic attraction at a given charge.

Bonding — What happens to potential energy as a stable bond forms?

It decreases to a minimum at the equilibrium bond distance.

Bonding — What is equilibrium bond length?

The internuclear distance where the potential energy is at a minimum.

Bonding — What is bond energy?

The energy required to break a bond; stronger bonds generally have larger bond energies.

Bonding — What generally happens to bond length as bond strength increases?

Stronger bonds are generally shorter.

Bonding — What is an octet?

Eight valence electrons around an atom, often corresponding to a stable noble-gas-like valence configuration.

Bonding — What is the common stable tendency of main-group atoms in Lewis structures?

Gain, lose, or share electrons to achieve an octet when applicable.

Lewis Structures — What does a Lewis symbol show?

An element symbol surrounded by dots representing its valence electrons.

Lewis Structures — What is the first step in drawing a Lewis structure?

Count the total valence electrons, adjusting for the charge if the species is an ion.

Lewis Structures — How do you account for a negative charge when counting Lewis electrons?

Add one electron for each negative charge.

Lewis Structures — How do you account for a positive charge when counting Lewis electrons?

Subtract one electron for each positive charge.

Lewis Structures — What is a skeletal structure?

The basic arrangement of atoms showing which atoms are connected by bonds.

Lewis Structures — Which atom is usually the central atom?

Usually the least electronegative atom, except hydrogen, which is never central.

Lewis Structures — What is a single covalent bond in a Lewis structure?

A shared pair of electrons between two atoms.

Lewis Structures — What is a lone pair?

A pair of valence electrons localized on one atom and not used in a bond.

Lewis Structures — What is the octet rule used for?

To evaluate whether atoms have appropriate valence-electron arrangements in a Lewis structure.

Lewis Structures — What is an electron-deficient molecule?

A molecule in which an atom can have fewer than eight electrons around it, such as some boron compounds.

Lewis Structures — What is an odd-electron species?

A species with an odd total number of valence electrons, so at least one atom cannot have a complete octet.

Lewis Structures — What is an expanded-valence molecule?

A molecule in which a central atom from period 3 or beyond can have more than eight electrons around it.

Lewis Structures — What is resonance?

When more than one valid Lewis structure represents the same connectivity and the actual structure is described by a resonance hybrid.