Atomic Structure

Atomic model: consists of protons, neutrons, and electrons
Protons and neutrons are in the nucleus, while electrons orbit around it
Electron configuration: arrangement of electrons in an atom
- Valence shell: outermost energy level, involved in chemical bonding
- Aufbau principle: electrons occupy lowest available energy levels
- Pauli's exclusion principle: each electron has a unique set of quantum numbers
Atomic radius: distance from the nucleus to the outermost electron
Ionization energy: energy required to remove an electron from an atom

Oxidation state: the charge an atom would have in a molecule if all bonds were ionic
Oxidation number: the charge an atom has in a molecule, can be positive or negative
Rules for assigning oxidation states:
- Free elements have an oxidation state of 0
- In compounds, the oxidation state of a monatomic ion is equal to its charge
- In compounds, the oxidation state of a metal is often positive
- In compounds, the oxidation state of a nonmetal is often negative
Examples of oxidation states:
- H2O: oxygen has an oxidation state of -2, hydrogen has an oxidation state of +1
- CO2: carbon has an oxidation state of +4, oxygen has an oxidation state of -2

Types of chemical bonds:
- Ionic bonds: formed between a metal and a nonmetal, involves transfer of electrons
- Covalent bonds: formed between two nonmetals, involves sharing of electrons
- Polar covalent bonds: formed between two nonmetals with different electronegativities
- Hydrogen bonds: weak bonds between hydrogen and a highly electronegative atom
Bonding theories:
- Valence shell electron pair repulsion (VSEPR) theory: predicts molecular shape based on electron arrangement
- Molecular orbital (MO) theory: describes the distribution of electrons in a molecule
Bond strength:
- Bond length: the distance between two atoms in a bond
- Bond energy: the energy required to break a bond

Electrochemical reactions: involve the transfer of electrons between species
Types of electrochemical reactions:
- Oxidation: loss of electrons, often occurs at the anode
- Reduction: gain of electrons, often occurs at the cathode
- Redox reaction: combination of oxidation and reduction reactions
Electrochemical cells:
- Galvanic cell: spontaneous reaction, generates an electric potential
- Electrolytic cell: non-spontaneous reaction, requires an external electric potential
Electrode potential: the potential difference between an electrode and a solution
Nernst equation: relates the electrode potential to the concentration of reactants

Types of organic reactions:
- Substitution reactions: involve the replacement of one functional group with another
- Elimination reactions: involve the removal of a functional group
- Addition reactions: involve the formation of a new bond
- Rearrangement reactions: involve the reorganization of a molecule
Reaction mechanisms:
- SN1 reaction: unimolecular nucleophilic substitution
- SN2 reaction: bimolecular nucleophilic substitution
- E1 reaction: unimolecular elimination
- E2 reaction: bimolecular elimination
Factors affecting reaction rates:
- Concentration: increasing the concentration of reactants can increase the reaction rate
- Temperature: increasing the temperature can increase the reaction rate
- Catalysts: substances that speed up the reaction without being consumed

Atom consists of protons, neutrons, and electrons
Protons and neutrons are in the nucleus, while electrons orbit around it
Electron configuration is the arrangement of electrons in an atom
Valence shell is the outermost energy level, involved in chemical bonding
Aufbau principle states that electrons occupy the lowest available energy levels
Pauli's exclusion principle states that each electron has a unique set of quantum numbers
Atomic radius is the distance from the nucleus to the outermost electron
Ionization energy is the energy required to remove an electron from an atom

Oxidation state is the charge an atom would have in a molecule if all bonds were ionic
Oxidation number is the charge an atom has in a molecule, can be positive or negative
Free elements have an oxidation state of 0
In compounds, the oxidation state of a monatomic ion is equal to its charge
Metals often have a positive oxidation state in compounds
Nonmetals often have a negative oxidation state in compounds
Examples of oxidation states include oxygen in H2O (-2) and carbon in CO2 (+4)

Electrochemical reactions involve the transfer of electrons between species
Oxidation involves the loss of electrons, often at the anode
Reduction involves the gain of electrons, often at the cathode
Redox reaction combines oxidation and reduction reactions
Galvanic cells involve spontaneous reactions, generating an electric potential
Electrolytic cells involve non-spontaneous reactions, requiring an external electric potential
Electrode potential is the potential difference between an electrode and a solution
Nernst equation relates the electrode potential to the concentration of reactants

Substitution reactions involve the replacement of one functional group with another
Elimination reactions involve the removal of a functional group
Addition reactions involve the formation of a new bond
Rearrangement reactions involve the reorganization of a molecule
SN1 reaction is a unimolecular nucleophilic substitution
SN2 reaction is a bimolecular nucleophilic substitution
E1 reaction is a unimolecular elimination
E2 reaction is a bimolecular elimination
Factors affecting reaction rates include concentration, temperature, and catalysts