Comprehensive Chemistry Review: Atomic Structure, Bonding, Reactions, and Kinetics

Practice vocabulary flashcards covering atomic structure, periodic trends, ionic and covalent bonding, metallic bonding, alloys, classification of chemical reactions, combustion, acids and bases, polymers, catalysts, and reaction rates.

Precipitation Reaction

A type of double displacement reaction occurring between ionic compounds in solution where an insoluble solid product forms.

Precipitate

A solid ionic compound produced during a precipitation reaction that does not dissolve easily in solution.

Spectator Ions

Ions that remain dissolved in solution throughout a reaction and do not participate in the formation of the precipitate.

Atomic Number ($Z$)

The number of protons found in the nucleus of an atom, which identifies the element and equals the number of electrons in a neutral atom.

Bohr Model

An atomic model stating that electrons exist only at specific energy levels represented by concentric electron shells around the nucleus.

Emission Spectrum

A unique pattern of light emitted by an element when its excited electrons transition from unstable higher energy levels back down to lower energy levels.

Endothermic Reaction

A chemical reaction that absorbs energy from its surroundings, resulting in products that store more chemical energy in their bonds and often have a lower temperature than the reactants.

Exothermic Reaction

A chemical reaction that releases energy to its surroundings, resulting in products that store less chemical energy in their bonds and often have a higher temperature than the reactants.

Synthesis Reaction

A chemical reaction where two or more reactants combine to form a single product, following the general formula $A + B \rightarrow AB$.

Decomposition Reaction

A chemical reaction in which a single reactant breaks down into two or more simpler products, following the general formula $AB \rightarrow A + B$.

Single Displacement Reaction

A reaction in which a more reactive element displaces another less reactive element in a compound, following the general formula $AB + C \rightarrow AC + B$.

Double Displacement Reaction

A chemical reaction in which two compounds exchange ions to form two new compounds, following the general form $AB + CD \rightarrow AD + CB$.

Oxidation

A chemical process involving the loss of electrons by a substance when it reacts with an oxidant.

Reduction

A chemical process involving the gain of electrons by a substance during a reaction.

Complete Combustion

The reaction of a hydrocarbon fuel with abundant oxygen producing carbon dioxide ($CO_2$) and water ($H_2O$).

Incomplete Combustion

The burning of a hydrocarbon fuel under limited oxygen supply, yielding water alongside toxic carbon monoxide ($CO$) and/or solid carbon soot ($C$).

Hydrocarbon

An organic compound consisting solely of hydrogen and carbon atoms held together by covalent bonds.

Neutralisation Reaction

A reaction where hydrogen ions ($H^+$) from an acid combine with hydroxide ions ($OH^-$) from a base to produce neutral water ($H_2O$) and a salt.

Acid-Metal Reaction

A reaction between an acid and a reactive metal producing a metal salt and hydrogen gas ($H_2$).

Acid-Metal Carbonate Reaction

A reaction between an acid and a metal carbonate yielding a metal salt, water, and carbon dioxide gas ($CO_2$).

Chemical Reaction

A process where reactant particles break chemical bonds, rearrange their atoms, and form new products with different properties.

Conservation of Mass

A scientific law stating that matter is neither created nor destroyed during a chemical reaction; the total quantity and types of atoms remain identical before and after the reaction.

Catalyst

A substance that increases the rate of a chemical reaction without being consumed or chemically altered in the process.

Activation Energy

The minimum energy barrier required for reactants to initiate bond breaking and proceed through a chemical reaction.

pH Scale

A logarithmic scale measuring hydrogen ion concentration in solution, calculated via $\text{pH} = -\log_{10}[H^+]$, typically ranging from 0 to 14.

Alkali

A base that dissolves in water to form a solution containing hydroxide ions ($OH^-$) with a pH greater than 7.

Metallic Bonding

The electrostatic attraction between fixed positive metal nuclei arranged in a regular lattice and a surrounding mobile 'sea' of delocalised electrons.

Delocalised Electrons

Outer-shell electrons in a metal that are not bound to any single atom, moving freely through the lattice to conduct heat and electricity and reflect light.

Alloy

A substance formed by combining a metal with one or more other metals or non-metals to modify and enhance physical and chemical properties.

Group (Periodic Table)

A vertical column in the periodic table containing elements with identical numbers of valence electrons and similar chemical properties.

Period (Periodic Table)

A horizontal row in the periodic table indicating the number of occupied electron shells possessed by an atom.

Electronegativity

A measure of an atom's ability to attract electrons towards itself when forming chemical bonds, which increases across a period and decreases down a group.

Allotropes

Different structural forms of the same element in the same physical state, resulting from different arrangements and bonding between atoms (such as diamond, graphite, and buckminsterfullerene).

Cation

A positively charged ion formed when an atom (typically a metal) loses one or more valence electrons.

Anion

A negatively charged ion formed when an atom (typically a non-metal) gains one or more electrons into its valence shell.

Ionic Bond

An electrostatic attraction formed between oppositely charged cations and anions following the transfer of electrons.

Polyatomic Ion

A tightly bound group of two or more atoms covalently bonded together that carries an overall net positive or negative electric charge.

Covalent Bond

A chemical bond formed when two non-metal atoms share pairs of valence electrons to achieve stable, full outer electron shells.

Diatomic Molecule

A molecule composed of exactly two atoms chemically bonded together, such as $H_2$, $O_2$, $N_2$, or $HF$.

Valence Electrons

Electrons residing in an atom's outermost shell that determine its chemical reactivity, bonding capabilities, and ion formation.

Polymer

A large molecule composed of repeating structural units bonded together in long chains, which can be synthetic (such as plastics) or natural (such as DNA).

Monomer

A small, reactive molecule that can undergo chemical bonding with other monomers to form a polymer chain.

Polymerisation

The chemical reaction process, typically requiring elevated temperature and pressure, where monomer molecules combine to create long-chain polymers.

Microplastics

Plastic particles less than $5\,mm$ in size, either manufactured directly (such as cosmetic microbeads) or formed from the breakdown of larger plastic debris.

Rate of Reaction

The speed at which reactants are transformed into products over time, measurable via changes in mass, volume of gas, temperature, or colour.

Collision Theory

A principle stating that for a chemical reaction to occur, reacting particles must collide with sufficient kinetic energy (activation energy) and in the correct geometric orientation.

Precipitate

An insoluble solid ionic compound produced during a chemical reaction between ionic compounds in solution that does not dissolve easily.

Spectator Ions

Ions present in a reaction mixture that remain dissolved in the aqueous solution and do not participate in the formation of the precipitate.

Solubility

A measure of how easily a substance dissolves in another substance (typically water); substances with solubility $> 1\,\text{g}/100\,\text{mL}$ are soluble, while those $< 0.1\,\text{g}/100\,\text{mL}$ are inso

Double Displacement Reaction

A chemical reaction in which two compounds react and exchange ions, with two cations swapping their bonded anions to form two new compounds.

Lithotripsy

A medical procedure that uses shock waves to break large kidney stones into smaller fragments so they can be passed naturally.

Alloy

A material produced by combining a metal with one or more other metals or non-metals to alter and enhance its physical and chemical properties.

Duralumin

A lightweight, strong aluminium alloy consisting of $91\%\text{ to }95\%$ aluminium ($\text{Al}$), $3.5\%\text{ to }4.9\%$ copper ($\text{Cu}$), $0.4\%\text{ to }1.8\%$ magnesium ($\text{Mg}$), and $0.3\%\text{ to }1.0\%$ manganese ($\text{Mn}$), invented by Alfred Wilm in 1906.

Nichrome

An alloy composed of $80\%$ nickel ($\text{Ni}$) and $20\%$ chromium ($\text{Cr}$) that resists corrosion, glows red-hot without melting, and is used for heating elements.

Cast Iron

A heavy-duty metal alloy composed of iron with $2\%\text{ to }4\%$ carbon and approximately $1\%\text{ to }3\%$ silicon, known for durability and exceptional heat retention.

Tin-Lead Solder

An alloy composed of $60\%$ tin and $40\%$ lead, utilized for joining electronic components on circuit boards and creating strong mechanical metal bonds.

Sterling Silver

A standard working metal alloy composed of $92.5\%$ pure silver and $7.5\%$ copper, which improves strength and durability while retaining shine.

Delocalised Electrons

Electrons in the outer shells of metal atoms that are not bound to any individual nucleus and can move freely throughout the metallic lattice.

Metallic Bonding

The electrostatic attraction holding a metal lattice together between positively charged metal nuclei and a surrounding mobile sea of delocalised electrons.

Atomic Number ($Z$)

The total number of protons located in the nucleus of an atom, identifying the element and matching the number of electrons in a neutral atom.

Valence Electrons

Electrons located in the outermost electron shell of an atom that govern its chemical properties, reactivity, and bonding capacity.

Emission Spectrum

The distinctive frequencies of light released when electrons in an atom drop from higher, unstable excited energy levels back to lower electron shells.

Electronegativity

A measure of an atom's ability to attract electrons towards itself, increasing with higher nuclear charge and decreasing with larger atomic radius and inner-shell electron shielding.

Periodic Reactivity Trends

Metal reactivity increases moving downwards and to the left across the periodic table, whereas non-metal reactivity (excluding inert noble gases) increases moving upwards and to the right.

Allotropes

Different structural forms of the same element in the same physical state arising from distinct arrangements of chemical bonds (e.g., diamond, graphite, and fullerenes for carbon).

Ionic Bond

A strong electrostatic force of attraction between oppositely charged ions (cations and anions) formed through the complete transfer of valence electrons.

Polyatomic Ion

A tightly bound group of atoms that behaves as a single unit and possesses an overall net positive or negative electrical charge (e.g., $\text{SO}_4^{2-}$, $\text{NH}_4^+$, $\text{OH}^-$).

Covalent Bond

A chemical bond formed between non-metal atoms through the mutual sharing of valence electron pairs to attain full, stable outer shells.

Diatomic Molecule

A particle composed of exactly two atoms bonded together chemically, such as $\text{H}_2$, $\text{O}_2$, $\text{N}_2$, or $\text{HF}$.

Endothermic Reaction

A chemical reaction that absorbs energy from the surrounding environment, resulting in products with greater stored bond energy and lower temperature than the reactants.

Exothermic Reaction

A chemical reaction that releases energy to the surrounding environment, producing substances with lower stored bond energy and higher temperature than the reactants.

Synthesis Reaction

A chemical transformation where two or more individual reactants combine to produce a single product ($A + B \rightarrow AB$).

Decomposition Reaction

A chemical process in which a single compound breaks down into two or more distinct products ($AB \rightarrow A + B$).

Single Displacement Reaction

A reaction in which a more reactive element substitutes for a less reactive element in a compound, represented by $AB + C \rightarrow AC + B$.

Oxidation

A chemical process involving the loss of electrons by a substance when it reacts with an oxidant, remembered by the OIL part of OILRIG.

Reduction

A chemical process involving the gain of electrons by an oxidizing agent during a reaction, remembered by the RIG part of OILRIG.

Combustion Reaction

An exothermic oxidation reaction occurring when a fuel (commonly a hydrocarbon) reacts rapidly with oxygen gas, emitting substantial heat and light.

Complete Combustion

The reaction of a hydrocarbon with abundant oxygen gas yielding solely carbon dioxide ($\text{CO}_2$) and water ($\text{H}_2\text{O}$).

Incomplete Combustion

The reaction of a hydrocarbon in an environment with limited oxygen, producing toxic carbon monoxide ($\text{CO}$) and/or carbon soot ($\text{C}$) alongside water.

Neutralisation Reaction

A reaction between an acid and a base in which hydrogen ions ($\text{H}^+$) combine with hydroxide ions ($\text{OH}^-$) to form neutral water ($\text{H}_2\text{O}$) and a salt.

pH Scale

A logarithmic measurement scale ranging typically from 0 to 14 quantifying the concentration of hydrogen ions in a solution: $\text{pH} = -\log_{10}([\text{H}^+])$.

Alkali

A water-soluble base that releases hydroxide ions ($\text{OH}^-$) in solution, producing a pH greater than 7.

Catalyst

A chemical substance that accelerates the rate of a chemical reaction without being consumed or chemically altered by providing a lower activation energy pathway.

Rate of Reaction

The speed at which reactants are transformed into products over time, detectable by changes in mass, volume of gas evolved, temperature, or colour.

Collision Theory

The theory stating that for a chemical reaction to occur, reactant particles must physically collide with sufficient kinetic energy (activation energy) and appropriate spatial orientation.

Conservation of Mass

The fundamental scientific law establishing that during chemical reactions, atoms are neither created nor destroyed; the total number and identity of atoms remain identical before and after the reaction.