Definition

Noun: 1. A process in which one or more substances are altered into one or more new and different substances: A chemical change involves the rearrangement of atoms and the breaking and forming of chemical bonds, resulting in substances with different chemical properties from the original materials. This process is also known as a chemical reaction.

Usage

• A chemical change is a fundamental concept in chemistry, describing transformations at the molecular level.
• It is often contrasted with a , where the form or state of matter changes but not its chemical identity.
• The term is used to describe processes where the starting materials (reactants) are converted into different products.

Examples

• The rusting of iron is a chemical change where iron reacts with oxygen and water to form iron oxide.
• Burning wood undergoes a chemical change, producing ash, smoke, and gases.
• Baking a cake involves a chemical change as the ingredients react to form a new substance with different properties.
• Digestion of food is a series of chemical changes that break down complex molecules.

Advanced Usage

• "To undergo a chemical change": This phrase describes the process happening to a substance.
  • When sodium is added to water, it undergoes a rapid chemical change.
• The concept is central to describing irreversible processes where the original substance cannot be easily recovered.

Variants and Related Words

• Chemical reaction (n): This is a direct synonym for chemical change, often used interchangeably in scientific contexts.
  • A chemical reaction always involves a chemical change.
• Chemical process (n): A broader term that can encompass chemical changes and other molecular phenomena.

Synonyms

• Chemical reaction
• Chemical transformation

Antonyms

• Physical change (a change in which the chemical identity of a substance remains the same, such as melting or dissolving).

Noun

1. (chemistry) any process determined by the atomic and molecular composition and structure of the substances involved