Unit 3 Vocabulary

Front

Reactivity

Back

Describes how fast elements gain or lose electrons to become stable.

Front

Valence Shell

Back

Outermost electron shell of an atom.

Front

Valence Electrons

Back

Electrons found in the outermost shell.

Front

Octet Rule

Back

The tendency of atoms to prefer to have eight electrons in the valence shell; 8 is great!

Front

Chemical Bond

Back

A force that unites atoms together into a compound.

Front

Ionic Bond

Back

Occurs when metals bond with non-metals; atoms gain or lose electrons to make a full valence shell.

Front

Covalent Bond

Back

Occurs when non-metals bond with non-metals; atoms share electrons to make a full valence shell.

Front

Law of Conservation of Mass

Back

States that the total mass in a closed system remains the same. In a chemical reaction, this means that the mass of the products of a reaction must equal the total mass of the original reactants.

Front

Chemical Change

Back

A change that occurs when one or more substances change into entirely new substances with different properties.

Front

Physical Change

Back

Changes the appearance of matter – size, shape, or state; no new substances are formed.