Chemical and Physical Properties vs Chemical and Physical Changes Tahoma Jr. High 8 th Science Ravensdale, WA

All substances have properties that we can use to identify them. For example we can identify a person by their: Physical and Chemical Properties facevoice heightfinger prints

There are two basic types of properties: Physical properties and Chemical properties We identified the people earlier with their PHYSICAL properties.

Examples of Physical Properties for things in Nature are: color smell boiling or melting point temperatures attraction or repulsion to magnets density

Examples of Chemical Properties are: temperature it ignites into flame

pH

reactivity with water (or other chemicals)

radioactivity (decays into a new element)

The more properties we can identify for a substance, the better we know how that substance works in Nature.

Physical Changes do not change the chemical makeup of the material. Examples include: Melting ice or boiling water Tearing paper

Chemical Changes A chemical change results in a new chemical or substance. A physical change does NOT create new chemicals !

Examples of Chemical Changes An iron nail rusting Iron is changing into iron oxide Wood burning Wood is changing into CO 2 and H 2 O Silver tarnishing Silver is combining with Sulfur in the air * after using a silver cleaing chemical

Chemical changes require the addition of energy or the release of energy Heat needed from environment (your body) to make the chemical reaction work

Show magnesium flashbulb and ribbon videos end show MAGNESIUM FLASHBULB IN SLOW MOTION (pure oxygen inside bulb makes it burn FAST!)