Reactions Concepts
27 concepts · Grades 6-8, 9-12 · 33 prerequisite connections
This family view narrows the full chemistry map to one connected cluster. Read it from left to right: earlier nodes support later ones, and dense middle sections usually mark the concepts that hold the largest share of future work together.
Use the graph to plan review, then use the full concept list below to open precise pages for definitions, examples, formulas, and related mistake guides. That combination keeps the page useful for both human study flow and crawlable internal linking.
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Concepts flow left to right, from foundational to advanced. Hover to highlight connections. Click any concept to learn more.
Connected Families
Reactions concepts have 19 connections to other families.
All Reactions Concepts
Synthesis Reaction
A chemical reaction in which two or more simple substances combine to form a single, more complex product.
Decomposition Reaction
A chemical reaction in which a single compound breaks down into two or more simpler substances.
Single Displacement
A reaction in which a more reactive element replaces a less reactive element in a compound.
Double Displacement
A chemical reaction in which the positive ions (cations) of two ionic compounds in aqueous solution exchange partners, forming two new ionic compounds. The reaction is driven by the formation of a precipitate, a gas, or water.
Combustion
A rapid exothermic reaction between a fuel and oxygen, producing carbon dioxide and water (for hydrocarbon fuels).
Precipitation Reaction
A double displacement reaction that produces an insoluble solid (precipitate) when two aqueous solutions are mixed.
Net Ionic Equation
An equation showing only the ions and molecules that actually participate in a reaction, with spectator ions removed.
Oxidation Number
A number assigned to an atom in a compound that represents the number of electrons it has gained, lost, or shared unequally.
Formula Writing
The process of combining element symbols and subscripts to represent the composition of a chemical compound.
Nomenclature
The systematic method for naming chemical compounds according to IUPAC rules, based on their composition and structure.
Chemical Reaction
A process where substances (reactants) are transformed into different substances (products).
Reactant
A starting substance that is consumed and chemically transformed during a chemical reaction, appearing on the left side of a chemical equation before the reaction arrow.
Product
A new substance formed as a result of a chemical reaction, appearing on the right side of a chemical equation, with different chemical properties from the original reactants.
Chemical Equation
A written representation of a chemical reaction using chemical formulas, coefficients, and an arrow.
Balancing Equations
Adjusting the coefficients in a chemical equation so each type of atom is equal on both sides.
Conservation of Mass
A fundamental law stating that in any chemical reaction, the total mass of all reactants exactly equals the total mass of all products, because atoms are rearranged but never created or destroyed.
Exothermic Reaction
A chemical reaction that releases energy (usually as heat or light) to the surroundings, resulting in an increase in surrounding temperature and a negative enthalpy change ($\Delta H < 0$).
Endothermic Reaction
A chemical reaction that absorbs energy (usually as heat) from the surroundings, resulting in a decrease in surrounding temperature and a positive enthalpy change ($\Delta H > 0$).
Activation Energy
The minimum kinetic energy that reactant particles must possess upon collision in order to break existing bonds and initiate a chemical reaction, represented as the energy barrier on a reaction energy diagram.
Catalyst
A substance that increases the rate of a chemical reaction by providing an alternative pathway with lower activation energy, without being permanently consumed or chemically altered in the process.
Reaction Rate
The speed at which reactants are converted into products in a chemical reaction, quantified as the change in concentration of a reactant or product per unit time.
Collision Theory
A model explaining that chemical reactions occur only when reactant particles collide with sufficient kinetic energy (at least equal to the activation energy) and in the correct geometric orientation.
Oxidation
The loss of electrons by an atom, ion, or molecule during a chemical reaction, resulting in an increase in its oxidation state. Oxidation always occurs simultaneously with reduction in a redox pair.
Reduction
The gain of electrons by an atom, ion, or molecule, decreasing its oxidation state.
Redox Reaction
A reaction in which electrons are transferred from one substance to another — one is oxidized, one is reduced.
Equilibrium Constant
A numerical value expressing the ratio of product concentrations to reactant concentrations at equilibrium.
Enthalpy
A thermodynamic quantity representing the total heat content of a system at constant pressure.