Synthesis

• Two or more substances combine to form another more complex substance.

A+B-->AB

Decomposition 

• One substance breaks down into two or more simpler substances

AB-->A+B

Single displacement

• Occurs when one element replaces another element in a compound 

A+By---> Ay+B

Double Displacement 

• Two different atoms in two different compounds exchange places 

Ay+Bx--->Ax+By

Combustion

• A hydrocarbon reacts with oxygen 
• The products of combustion are always water and carbon dioxide
• Hydrogen + Oxygen

----> water+carbon Dioxide 

When we lit the steel wool on fire it was an example of synthesis 

Fe+ O2+fe O3

An example of Decomposition is when the baking soda was heated 

NaHCO3------>H2O + Co2+ NAOH

an example of single displacement is the nail in sulfate

FG+CCuSOU----->CU+FE2(SO4)3