September, 28 2010 - Matter

On September, 28 2010 we reviewed on the things that we had learned in the past about matter. We took some notes on what matter is to help use remember the specific definition of matter.  




 Here is a link to check out this video.

http://www.youtube.com/watch?v=-Ypwtjp0FSE




Matter is divided into two categories. One is pure substances and the other is mixtures.

Pure substances 

• have one set of properties
• have only one kind of particle

Pure substances are spit into two parts. Pure substances are either Elements or Compounds.

Elements:

• are the simplest form (It cannot be decompose)
• are made of atoms

Compounds:

• are made of elements
• are chemically combined
• are the smallest particles
• are molecules (either inonic or covalent)

Mixtures

• have more than one set of properties and substances
• are physically combined

Mixtures are split into two categories as Homogeneous and Hetrogeneous.

Homogeneous:

• are uniformed throughout
• appears to have only one compound. Ex. solution.

Hetrogeneous:

• not uniform
• appears to have mroe than one component. Ex. Water and oil. Salade dressing.

         The properties of matter have physical and chemical changes as the environment around the matter changes. Physical changes are changes that you can see with the naked eye while chemical changes may not necessarily be visible. In physical changes, no new substance is formed. The chemical composition does not change. Matters that undergoes physical changes can be reversible. For example, melting point and boiling point. On the other hand during a chemical change, new substances are produced. Unlike physical changes, the changes that occur in chemcial changes are irreversible. For example, you cannot uncook a food that was already cooked.