Physical/Chemical Properties and Changes

Physical Properties

• The property depends on the substance itself

Extensive

• Depends on the amount

• Ex: mass, time it takes for a liquid to evaporate

Intensive

• Doesn’t depend on the amount

• Ex: density, melting point, color

Chemical properties

• depends on the action of one substance on another

• Ex: flammability, reacts with water…

Physical Changes

• Alters a substances identity without changing its chemical composition

• No new substance is produced

• Ex: melting, freezing, crushing, boiling, any change in state

Chemical changes

• one or more of the substances are changed into new substances

• Ex: burn, rust, baking a cake, gas, unexpected color change, temperature change, forming a precipitate (a solid is formed when two liquids are added)

Kinetic

energy of motion

potential

stored energy

radiant

energy from the sun

law of conservation of energy

energy cannot be created of destroyed in a chemical reaction

exothermic reaction

• release energy to surroundings

• feels hot

endothermic reaction

• absorb energy

• feels cold