How do stalactites and stalagmites form? What will be an ideal ...

[Melani1276]

How do stalactites and stalagmites form?
 
  What will be an ideal response?

Question 2

All of the following pollutants were targeted for reduction by 2010, according to The 1999 Protocol, except ________.
 
  A) nitrous oxide
  B) ammonia
  C) sulfur dioxide
  D) CFCs
  E) VOCs

[FergA]

Answer to Question 1

Stalactites form when groundwater seeps through cracks in the ceiling of a cavern. When the water reaches air inside the cave, some of the dissolved carbon dioxide escapes from the drop, and calcite begins to precipitate. Deposition occurs as a ring around the edge of the water drop, and as drop after drop follows, each leaves a trace of calcium behind, thus creating a hollow limestone tube. Often the hollow tube becomes plugged or the supply of water increases, forcing water to flow and deposit along the outside of the tube. As deposition continues, the stalactite becomes more conical in shape. Stalagmites form on the cavern floor when water falls from the cavern ceiling. The drops deposit calcium, which slowly builds a formation that slowly grows toward the ceiling.

Answer to Question 2

D