The world around us is constantly changing. Some of these changes result from substances undergoing
phase changes, such as ice melting or water boiling. Some of these changes results in totally different products being
formed. We will look at both of these kinds of changes.
Physical Changes - are changes of phase and DO NOT result
in the formatio of a new product
- Examples include: melting, vaporization, sublimation, condensation and freezing
Chemical Changes - result from chemical reactions and new
products are formed
- Examples include: burning of paper and thousands of other chemical interactions
Chemical Equations
A chemical equation shows what takes place during a chemical reaction. It is similiar to an
algebraic equation in that what is written on one side of the equation equals what is written on the other side. An
arrow is used instead of an equal sign to seperate the sides of the equation. The arrow is read produces or yields.
A chemical reaction consists of two parts:
Reactants: are what goes INTO the reaction and are written on the LEFT SIDE of
the equation
Products: are what COMES OUT of the reaction (is produced) and is written on
the RIGHT SIDE of the
For Example
Reactions can either RELEASE energy or ABSORB
energy
