Skip to content
Know.itKnow.it
Create an animated lesson
On request

This article is free to read. Creating a lesson uses your daily or stored credits; review the language and settings before starting.

What is the conservation of mass?

ScienceLesson on requestFree to read

Quick answer

The conservation of mass is the principle that matter cannot be created or destroyed in a chemical reaction — only rearranged. The total mass of the substances before a reaction equals the total mass after, even as new substances form.

Key things to understand

  1. Matter isn't created or destroyed in reactions.
  2. Atoms are just rearranged into new substances.
  3. Total mass before = total mass after a reaction.
  4. It's a foundation of chemistry and balancing equations.

People also ask

What is the conservation of mass?
The principle that the total mass stays the same in a chemical reaction — matter is only rearranged.
Who discovered the conservation of mass?
Antoine Lavoisier is credited with establishing it in the 18th century.
Why does mass stay the same in a reaction?
Because atoms are neither created nor destroyed — they just recombine into different molecules.