Science 9/14/10

Bell Question:  Name each symbol:  Are elements homogeneous or heterogeneous?

   N-  Nitrogen

   Br- Bromine

   Na-Sodium

   K-  Potassium

   Cu- Copper

- Elements are Homogeneous because they involve compound and compounds are homogeneous.

Compound: combination of elements

                   CO2   NH3

Atomic Number =

Number of Protons   =         All the Same Number

Number of Electrons=

Protons + neutrons= Atomic Mass

Physical Properties- properties that describe the matter

* color, mass, inertia, volume, density, temperature, texture, weight, shape, etc.

Chemical Properties- the way a chemical change occurs

* rusting, burning, chemical reaction, ionization energy, electronegative, etc.

Density =    mass

                    volume