1.3 Physical and Chemical Properties

Properties of Matter

Characteristics that distinguish one substance from another; divided into Physical and Chemical properties.

Physical Properties

Characteristics of matter not involving a chemical change. Examples: density, color, hardness, melting/boiling points, electrical conductivity.

Chemical Properties

Characteristics that describe a substance's ability or inability to change into a different substance. Examples: flammability, toxicity, acidity, reactivity.

Physical Change

Change in state, form, or appearance without altering chemical identity; no new substance formed. Examples: wax melting, steam condensing, sugar dissolving, grinding solids, magnetizing/demagnetizing.

Chemical Change

Produces one or more new substances with different chemical identities. Examples: rusting of iron, combustion, cooking food, banana browning, nitroglycerin explosion.

Key Difference: Physical vs Chemical Change

Physical changes do not change identity; chemical changes create new substances.

Extensive Property

Depends on the amount of matter present. Examples: mass, volume, total heat content.

Intensive Property

Independent of the amount of matter. Examples: temperature, density, color, boiling point.

Milk Example of Extensive vs Intensive

Gallon vs cup: mass and volume increase (extensive), temperature remains the same (intensive).

Cooking Oil Example of Extensive vs Intensive

Drop vs pot: same temperature (intensive), different total heat content (extensive).

Hazard Diamond Purpose

Provides safety information about a substance's hazards (NFPA system).

Hazard Diamond: Red (Top)

Fire hazard (flammability), rated 0–4.

Hazard Diamond: Blue (Left)

Health hazard, rated 0–4.

Hazard Diamond: Yellow (Right)

Reactivity hazard, rated 0–4.

Hazard Diamond: White (Bottom)

Special hazard information (oxidizer, corrosive, water-reactive, radioactive, biological hazard, etc.), rated 0–4.

Hazard Diamond Scale

0 = no hazard, 4 = extremely hazardous.