Properties and Changes in Matter

PROPERTIES OF MATTER

Physical Properties

• Can be observed or viewed without changing the sample’s composition– Example: density, color, odor, state of

matter, boiling point, melting point, shape

– Use your senses

Properties

Extensive• Properties that depend

on the amount of substance present

• Example: Volume, mass

Intensive• Properties that are

independent of the amount of substance present

• Can be used to identify a substance

• Example: density, boiling point, temperature

Chemical Properties

• How a substance interacts with another substance (ability or inability)

• Example: iron can react with oxygen, carbon dioxide is not flammable

CHANGES IN MATTER

Physical Changes

• Alter a substance without changing the composition

• Example: bend, grind, crumple, split, phase change

Chemical Changes

• Process in which a substance(s) is changed into one or more new substances

• Example: combust, ferment, burn, rot, tarnish

• Also known as a chemical reaction

Chemical Equation

• Use of symbols to represent a chemical reaction

• Example: CH4 + O2 → CO2 + H2O

Reactants• Starting substances• Found on the left hand

side of a chemical equation

Products• Substances formed• Found on the right

hand side of a chemical equation

Law of Conservation of Mass

• Mass is neither created or destroyed during a chemical reaction

• Mass of the reactants = mass of the products

Chemical Reaction Signs• Bubbling (gas production)• Color change• Precipitate forms (solid formation)• Energy change (temperature

change)• The only way to know for sure

is to check the composition before and after!!