MCAT GENERAL CHEMISTRY REVIEW
EXAM WITH ANSWERS.
Atomic Number (Z) - Answers-# of Protons
Mass Number (A) - Answers-# of protons + # of neutrons
Charge (c) - Answers-Number of protons - # of electrons
Does energy increase or decrease with distance from the nucleus? - Answers-Increase
Does distance increase or decrease with distance from the nucleus? - Answers-
Decrease
Quantum number n - Answers-Describes the radial distance of an electron's orbit from
the nucleus
Absorption (Absorbing a photon) - Answers--Positive change in energy
-Endothermic
-Jump to a higher energy level
Emission (Emitting a photon) - Answers--Negative change in energy
-Exothermic
-Drop to a lower energy level
Energy of Photon Equation - Answers-Ephoton = Ef - Ei
Energy of Photon in Relation to Wavelength and Frequency Equation - Answers-E = hf
= hc/λ
-h is a constant
-c is the speed of light
Orbital Energies - Answers-Increase with complexity of orbital shape (s<p<d<f)
Degenerate - Answers-Same energy
Aufbau Principle - Answers-Describes how electrons are added to or removed from
orbitals of different energy
Hund's Rule - Answers-Describes how electrons are added to or removed from orbitals
of the same energy
Pauli Principle - Answers-Describes the carrying capacity of an orbital
Valence Electrons - Answers-In highest energy shell
,Where are electrons added to? - Answers-From lowest to highest energy orbitals
Where are electrons removed from? - Answers--From highest to lowest energy orbitals
-Exception: 4s valence electrons are removed before 3d non-valence electrons
Paramagnetic - Answers-At least one unpaired electron (attracted by magnet)
Diamagnetic - Answers-All electrons are paired (repelled by magnet)
Ground State - Answers-Lowest energy electron configuration
Electron Configuration Exceptions - Answers--Chromium: [Ar] 4s1 3d5
-Copper: [Ar] 4s1 3d10
Same Group Elements (going down) - Answers-Similar reactivity
Have No Fear Of Ice Cold Beer - Answers--H = gas
-N = gas
-F = gas
-O = gas
-I = solid (ice)
-Ch = gas
-Br = liquid (beer)
Effective Nuclear Charge - Answers-Nuclear charge experienced by valence electrons
Moving down a group... - Answers--Core electrons are added at the same rate as
protons (Zeff is constant)
-Number of valence electrons remains the same (C remains zero)
-Size of the valence shell increased (n increases)
-Fe decreases
Moving left to right across a row... - Answers--Number of core electrons remain constant
while protons are added (Zeff increases)
-Valence electrons are added at the same rate as protons (C remains zero)
-Size of the valence shell remains constant (n remains constant)
-Fe increase
Moving from positive to negative charge... - Answers--Number of core electrons and
protons remains constant (Zeff remains constant)
-Number of valence electrons increases while the number of protons remains constant
(C becomes more negative)
-Size of valence shell remains constant (n remains the same)
-Fe decrease with increasing negative charge
, Atomic Radius Trend - Answers--Increases going down a group
-Decreases going left to right
Ionic Radius Trend - Answers--Increases with increasing negative charge
Ionization Energy - Answers--Minimum amount of energy required to remove the outer
most electron from an atom in its gaseous state
-Increases with more positive charge
Ionization Energy Trend - Answers-- Increases going up a group
-Increases going left to right
Electron Affinity - Answers-Energy change when adding an electron to the valence shell
of an atom in its gaseous state
Electron Affinity Trend - Answers--Increases going up a group
-Increases going left to right
Electronegativity - Answers-Ability of an atom to attract electrons to itself in a covalent
bond
Electronegativity Trend - Answers--Increases going up a group
-Increases going left to
right
-F>O>N>Cl>Br>I>S>C~H
Lewis Dot Structures - Answers--Valence electrons (neg. charge = +1 e- and pos.
charge = -1 e-)
-Arrange for least electronegative atom in the center
-Positive charges on less electroneg. atoms
-Negative charges on more electroneg. atoms
Geometric Shape Of Bond - Answers--2 groups = sp = linear
-3 groups = sp2 = trigonal planar
-4 groups = sp3 = tetrahedral
Strength of Chemical Bond - Answers--More electrons shared = stronger bond
-Shorter distance between atoms = stronger bond
-Stronger bond = higher bond dissociation energies
Breaking a Bond - Answers-Endothermic
Forming a Bond - Answers-Exothermic
Covalent Bonds - Answers--High electroneg.
-Nonmetals with nonmetals
EXAM WITH ANSWERS.
Atomic Number (Z) - Answers-# of Protons
Mass Number (A) - Answers-# of protons + # of neutrons
Charge (c) - Answers-Number of protons - # of electrons
Does energy increase or decrease with distance from the nucleus? - Answers-Increase
Does distance increase or decrease with distance from the nucleus? - Answers-
Decrease
Quantum number n - Answers-Describes the radial distance of an electron's orbit from
the nucleus
Absorption (Absorbing a photon) - Answers--Positive change in energy
-Endothermic
-Jump to a higher energy level
Emission (Emitting a photon) - Answers--Negative change in energy
-Exothermic
-Drop to a lower energy level
Energy of Photon Equation - Answers-Ephoton = Ef - Ei
Energy of Photon in Relation to Wavelength and Frequency Equation - Answers-E = hf
= hc/λ
-h is a constant
-c is the speed of light
Orbital Energies - Answers-Increase with complexity of orbital shape (s<p<d<f)
Degenerate - Answers-Same energy
Aufbau Principle - Answers-Describes how electrons are added to or removed from
orbitals of different energy
Hund's Rule - Answers-Describes how electrons are added to or removed from orbitals
of the same energy
Pauli Principle - Answers-Describes the carrying capacity of an orbital
Valence Electrons - Answers-In highest energy shell
,Where are electrons added to? - Answers-From lowest to highest energy orbitals
Where are electrons removed from? - Answers--From highest to lowest energy orbitals
-Exception: 4s valence electrons are removed before 3d non-valence electrons
Paramagnetic - Answers-At least one unpaired electron (attracted by magnet)
Diamagnetic - Answers-All electrons are paired (repelled by magnet)
Ground State - Answers-Lowest energy electron configuration
Electron Configuration Exceptions - Answers--Chromium: [Ar] 4s1 3d5
-Copper: [Ar] 4s1 3d10
Same Group Elements (going down) - Answers-Similar reactivity
Have No Fear Of Ice Cold Beer - Answers--H = gas
-N = gas
-F = gas
-O = gas
-I = solid (ice)
-Ch = gas
-Br = liquid (beer)
Effective Nuclear Charge - Answers-Nuclear charge experienced by valence electrons
Moving down a group... - Answers--Core electrons are added at the same rate as
protons (Zeff is constant)
-Number of valence electrons remains the same (C remains zero)
-Size of the valence shell increased (n increases)
-Fe decreases
Moving left to right across a row... - Answers--Number of core electrons remain constant
while protons are added (Zeff increases)
-Valence electrons are added at the same rate as protons (C remains zero)
-Size of the valence shell remains constant (n remains constant)
-Fe increase
Moving from positive to negative charge... - Answers--Number of core electrons and
protons remains constant (Zeff remains constant)
-Number of valence electrons increases while the number of protons remains constant
(C becomes more negative)
-Size of valence shell remains constant (n remains the same)
-Fe decrease with increasing negative charge
, Atomic Radius Trend - Answers--Increases going down a group
-Decreases going left to right
Ionic Radius Trend - Answers--Increases with increasing negative charge
Ionization Energy - Answers--Minimum amount of energy required to remove the outer
most electron from an atom in its gaseous state
-Increases with more positive charge
Ionization Energy Trend - Answers-- Increases going up a group
-Increases going left to right
Electron Affinity - Answers-Energy change when adding an electron to the valence shell
of an atom in its gaseous state
Electron Affinity Trend - Answers--Increases going up a group
-Increases going left to right
Electronegativity - Answers-Ability of an atom to attract electrons to itself in a covalent
bond
Electronegativity Trend - Answers--Increases going up a group
-Increases going left to
right
-F>O>N>Cl>Br>I>S>C~H
Lewis Dot Structures - Answers--Valence electrons (neg. charge = +1 e- and pos.
charge = -1 e-)
-Arrange for least electronegative atom in the center
-Positive charges on less electroneg. atoms
-Negative charges on more electroneg. atoms
Geometric Shape Of Bond - Answers--2 groups = sp = linear
-3 groups = sp2 = trigonal planar
-4 groups = sp3 = tetrahedral
Strength of Chemical Bond - Answers--More electrons shared = stronger bond
-Shorter distance between atoms = stronger bond
-Stronger bond = higher bond dissociation energies
Breaking a Bond - Answers-Endothermic
Forming a Bond - Answers-Exothermic
Covalent Bonds - Answers--High electroneg.
-Nonmetals with nonmetals
