• an initial d shirt...so cool lor...perhaps i m wearin it for be yorself dae...
• an initial d notebook...got pixs of mani actors in it lyk jay chou...he so shuai lor...
• an intial d calendar...from july 2005 to dec 2006 lor...so useful sia...
• an initial d poster...its da pix of jay chou...oso da biggest poster i haf eva seen...dose display on bus-stop dat type...so big horx...
• 4 new flavours of halls lorx...one each..
• most importantly is da sneak preview movie ticket...hahax...

feel so lucky cux i juan dao alot 2dae...quite a number of free gifts lor...dun get jealous hor u all...hehehehe...tink i was smiling in my slp last nite lorx...tym for lunch le...*puff*

• Decomposition of rocks in situ when the minerals in the rock react with other agents. (rainwater, carbon dioxide, oxygen)
• These chemicals changes weakens the rock and alters the physical structure and chemical composition of the rock.
• Changes vary from a simple change in colour to a change in the composition and qualities of the rock.

There are 6 types of chemical weathering.

1) Solution

• The dissolving of minerals in water that enter the rock formation. When these minerals are dissolved, they leave behind a void, which as it increases in size, causes changes in the rock structure, and causes the rock to crumble.
• A usual result are cavities in a rock body. (honeycomb effect)

2) Carbonation

• When carbon dioxide dissolves in water, it becomes carbonic acid.
• Carbonic acid is especially reactive with limestone.
• Limestone has a chemical element call calcium carbonate. (CaCO3)
• When mixed with carbonic acid, it forms a new substance called calcium hydrogen carbonate which is soluble and easily removed.
• The chemical equation for this process is as follow : CaCO3 + H2CO3 --> Ca(HCO3)2
• Causes widening of joints as the sides dissolves, and results in deepened joints named grikes.
• A larger version of grikes are clints.
• Limestone hills are known as karsts.

3) Hydrolysis

• Chemical reaction between inherent chemicals and water.
• This alters the minerals in the rocks into other minerals. The rocks are thus weakened and fall apart into finer particles.
• Hydrolysed feldspar and mica in granite form kaolin. (clay)

4) Oxidation

• Takes place when inherent minerals react with oxygen and water.
• A commonly oxidised mineral is iron. When oxidised, the iron changes into a reddish-brown iron oxide which crumbles easily.
• Ferrous --- Ferric state simply means an addition of an oxygen element into the iron body. FeO --> Fe2O3

5) Hydration

• Absorption of water by minerals in the rocks. This leads to a swelling, producing stresses in the rocks.

6) Spheroidal Weathering

• Specific to magmatic rocks.
• Forms jointed rocks which are angular and block like in nature. (think of cadbury chocolate bars.)
• The weaker rock elements at the joints and the inherent minerals are weathered when the minerals dissolve in flowing water. This weathered layer becomes thicker and the core rock becomes spheroidal.

whoa...now going 5am liao...slp for a while first b4 heading 4 skol...hahax...yawnzzz...finalli finished my geog!!!!