Definition

1. Noun:
   • A process in chemistry: A chemical reaction is a process where one or more starting substances, called reactants, are transformed into one or more different substances, called products. This involves the breaking and forming of chemical bonds between atoms.

Usage

• The term is used to describe the fundamental event in chemistry where matter changes its identity.
• It is a countable noun (e.g., "a reaction," "several reactions").
• It is often discussed in terms of reactants, products, energy changes (exothermic or endothermic), and the conditions required (e.g., heat, light, a catalyst).

Examples

• Noun:
  • The rusting of iron is a slow chemical reaction between iron, oxygen, and water.
  • Combustion, such as burning wood, is a rapid chemical reaction that releases heat and light.
  • Scientists observed a new chemical reaction in the laboratory.
  • Baking a cake involves several chemical reactions, like the reaction of baking soda with acid to produce carbon dioxide gas.

Advanced Usage

• "To undergo a chemical reaction": Describes when a substance participates in and is changed by the process.
  • When sodium metal is added to water, it undergoes a violent chemical reaction.
• "To catalyze a chemical reaction": To speed up a reaction using a substance (a catalyst) that is not consumed in the process.
  • Enzymes are biological molecules that catalyze specific chemical reactions in cells.

Variants and Related Words

• Reaction (n): In a general or chemical context, this is a common short form for .
  • The reaction was complete in under a minute.
• Reactant (n): A substance that takes part in and undergoes change during a .
• Product (n): A substance formed as a result of a .
• Reactivity (n): The tendency of a substance to undergo a .

Synonyms

• Chemical change: A process that results in the transformation of one substance into another with different properties.
• Chemical transformation: A formal term for a .

Related Phrases

• Rate of reaction: The speed at which a proceeds.
  • Increasing the temperature usually increases the rate of reaction.
• Reaction mechanism: The step-by-step sequence of elementary reactions by which an overall occurs.
• Reversible reaction: A where the products can react to re-form the original reactants.

Noun

1. (chemistry) a process in which one or more substances are changed into others
   • there was a chemical reaction of the lime with the ground water