Definition

1. Noun:
   • A fundamental principle of classical physics stating that matter cannot be created or destroyed in an isolated system: This law asserts that the total mass of substances involved in a physical change or chemical reaction remains constant when measured in a closed system.

Usage Examples

• Noun:
  • The experiment was designed to demonstrate the law of conservation of mass.
  • According to the law of conservation of mass, the mass of the reactants must equal the mass of the products in a chemical reaction.

Advanced Usage

• In the context of modern physics: While still a cornerstone of chemistry, it is noted that in nuclear reactions, mass can be converted to energy, as described by Einstein's mass-energy equivalence principle. The classical law of conservation of mass is thus seen as a special case of the more general law of conservation of mass-energy.
  • The law of conservation of mass is rigorously applicable in all non-nuclear chemical processes.

Variants and Related Words

• Conservation of mass: A synonymous phrase often used interchangeably.
• Principle of mass conservation: Another equivalent term.
• Law of conservation of matter: A closely related term, sometimes used synonymously, though "mass" is the more precise scientific quantity.

Synonyms

• Mass conservation
• Principle of indestructibility of matter (a more historical term)

Related Phrases

• Closed system: A system where no matter can enter or leave, which is a key condition for the law to hold.
• Mass balance: A practical application of the principle in engineering and chemistry to account for all mass in a process.

Noun

1. a fundamental principle of classical physics that matter cannot be created or destroyed in an isolated system