Conservation of Mass - 7th Grade Science

Vocabulary flashcards covering the key terms and definitions for 7th Grade Science on the Conservation of Mass.

Mass

The amount of matter contained in an object or substance.

Closed System

A space where matter cannot enter or leave during a physical change or chemical reaction.

Conservation of Mass

The principle that mass cannot be created or destroyed in a closed system, so total mass remains constant during any change or process.

Mixture

A physical combination of two or more substances where each substance retains its own properties and can be separated by physical means.

Element

The simplest building block of matter, made of only one kind of atom, which cannot be broken down by physical or chemical means.

Compound

A pure substance made from two or more different elements chemically combined in fixed proportions.

Molecule

A group of two or more atoms joined chemically, which can represent elements (such as $O_2$) or compounds (such as $H_2O$).

Volume

The amount of space an object or substance takes up.

Filtration

A separation method that uses a filter to separate solid particles from liquid in a mixture.

Sifting

A physical separation method that uses a sieve to separate larger particles from smaller particles.

Evaporation

A separation process involving heating a liquid to make it vaporize, leaving behind dissolved solid particles.

Magnetism

A physical separation method using a magnet to pull out magnetic substances (such as iron filings) from a mixture.

Decanting

A process used to separate liquids of different densities by pouring off the top less dense layer.

Reactants

The starting substances present before a chemical reaction takes place.

Products

The new substances formed as a result of a chemical reaction.