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Showing posts with label jom study. Show all posts
Showing posts with label jom study. Show all posts

Tuesday, January 11, 2011

STATE OF MATTER ?

Matter is classify in two type:

Elements is the simplest form of matter which can not be changed further by chemical or physical methods. An ATOM is the simplest form of an element, some elements is a MOLECULE.

Compound contain two or more different elements in a chemically combined form. The simplest form of a compound is a molecule.Those molecules that consist of charged ions with opposite charges are called IONIC. The other type of molecules are called COVALENT and do not consist of ions.


Elements consist same type atom


See example of ELEMENTS
SYMBOLCOMMON ELEMENTS
TYPE OF ELEMENTS
Cl2Chlorinemolecule
ArArgonatom
NeNeonatom
XeXenonatom
H2Hydrogenmolecule
MgMagnesiumatom
NaSodiumatom
O2Oxygenmolecule


Compound consist different type of atom and chemically combined.

See example of COMPOUND

SYMBOLCOMMON COMPOUNDS
TYPE
H2Owatercovalent / molecule
CO2carbon dioxidecovalent / molecule
NH3ammoniacovalent / molecule
NaClsodium chloride (Table Salts)ionic / ion
MgOmagnesium oxideionic / ion
Fe2O3iron oxide (Rust)ionic / ion
HClhydrogen chloridepolar covalent / molecule

Sunday, December 19, 2010

JOM BELAJAR CHEMISTRY

DIFFUSION

Tak susah pun topik ni...tapi ramai students misconcept / cuai / confused (keliru) ... lebih teruk lagi tak paham soalan untuk jawab soalan tentang part ni.

Konsep Asas - kita kena paham konsep "pergerakan zarah"(particles movement) dan "ruang"(space).

What is Diffusion ? [ Apa itu proses resapan]

Situation I
Pada waktu tengahari sedang anda melayan facebook di bilik bacaan. Anda terhidu sesuatu bau di bilik anda.. Berbau wangi, sedap menusuk hidung sehingga berbunyi perut anda kerana lapar. Bau tersebut datangnya dari dapur, bau masakan kari kepala ikan...Mak yang masak.

Adakah anda sedari proses resapan (diffusion process) berlaku dalam situasi di atas?

" Bau masakan kari di dapur merebak hingga ke bilik bacaan"
"The smell of curry cooking in the kitchen spreads to the study room"



Smell travel in the air by diffusion process. Molecules move randomly and freely in the air. Remember, molecules always moving, some molecules leave the curry as it is cooking. Molecules released when curry heated over.

These tiny molecules of curry travel through the air throughout the house-study room to our noses. If the wind is blowing, there will be more mixing of the molecules in the air, and molecules of curry can travel farther apart to other places. The molecules move randomly "from concentrated area(region) to less concentrated area(region)".

REMEMBER : Molecules* move randomly/freely from high concentrated region to low concentrated region.
* Air molecules

INGATLAH : Molekul bergerak secara rawak dan bebas dari kawasan berkepekatan tinggi ke kawasan berkepekatan rendah.



JOIN DISCUSSION : ANY QUESTIONS?