Physical and Chemical Changes and Reaction Types

Vocabulary flashcards covering the definitions, observations, comparative features, and reaction types of physical and chemical changes.

Physical Change

A change in which the form or appearance of matter alters, but its chemical identity remains exactly the same, and no new substance is created.

Chemical Change

A process where one or more substances are transformed into entirely new substances with different chemical properties, in which atomic bonds are broken and reformed.

Endothermic

A property of a chemical mix that absorbs energy, causing the liquid to get cooler and noticeably cold to the touch on the outside of the container.

Gas Evolution

An observation characterized by a fast burst of bubbles and fizzing upon contact, producing carbon dioxide ($CO_2$) gas.

Color Changes in Baking Soda and Vinegar

An observation where plain baking soda (white powder) and plain vinegar (clear liquid) form a cloudy, white-foamy mixture with no change in color.

Reversibility (Physical vs. Chemical)

A distinction where physical changes are usually temporary and reversible, whereas chemical changes are permanent and irreversible.

Energy Shifts (Physical vs. Chemical)

A distinction where physical changes involve minimal energy shifts, while chemical changes often involve noticeable energy absorption or release.

Combination (Synthesis)

A reaction type where two or more substances combine to form one product, represented by the formula $A + B \rightarrow AB$.

Decomposition

A reaction type where one substance breaks down into simpler substances, represented by the formula $AB \rightarrow A + B$.