chemical+and+physical

There are two types of properties that are used to describe matter: physical and chemical properties.

A //**physical property**// involves observable features, such as:
 * color[[image:boiling water.jpg width="251" height="165" align="right"]]
 * phase
 * odor
 * pliability
 * melting point
 * boiling point
 * density

There are a few //physical changes// a substance can undergo (one where the chemical makeup is not altered):
 * melting[[image:iodine sublim.jpeg align="right" caption="Sublimation of iodine crystals into vapor."]]
 * solidifying
 * evaporating
 * condensing
 * subliming
 * deposition
 * dissolving (ex. sugar dissolving in water)


 * Question**: describe the physical properties of the crystal of bismuth, shown below.



//**Chemical properties**// describe how a substance interacts with other substances. Examples:
 * hydrochloric acid will digest food
 * gasoline will combust in the presence of oxygen
 * TNT is explosive

A //chemical change// will alter the atomic arrangement of a substance, and will render it a new substance.

Here are some examples of chemical changes:
 * combustion
 * decomposition
 * oxidation (rusting, tarnishing)
 * effervescence (release of a gas)
 * corrosion
 * inertness (lack of chemical activity)


 * Question:** describe what kinds of chemical changes are occurring in the following images.

Try your hand at some online practice questions and some more multiple choice problems.

Download and print a practice worksheet: