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tacang.... |
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The Octet Rule
The octet rule states that atoms are most stable when they have a full shell of 8 electrons in the outside electron shell.
Octet = 8
An atom with eight electrons in the outer shell is more stable than an atom which as fewer electrons in the outer shell.
The exception to this is Helium (atomic number 2) which only has two electrons in its outer shell. It has a full shell, so it is a stable inert element.
Valence electrons are the only electrons involved in chemical bonds.
Atoms will form chemical bonds with other atoms by either sharing electrons, or by transferring electrons in order to complete their octet and get 8 electrons in the outer shell. |
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ions
In a stable atom, the number of electrons is equal to the number of protons.
An atom which has a different number of electrons than it does protons is called an ion.
Ions are charged particles. Types of ions:
1. Cation - A positively charged ion.
A cation is an atom or group of atoms with a net positive charge, caused by the loss of one or more electrons.
Examples: Na+, NH4+, Mg+2
2. Anion - a negatively charged ion.
An anion is an atom or group of atoms with a net negative charge, caused by the gain of one or more electrons.
Examples: F-, S2-, NO3-
3. Polyatomic ion - a group of atoms which function as a group and which has a net positive or negative charge (cation or anion).
Examples: NH4+ or NO3-
The Periodic Chart can show how the octet rule works. All of the Group I elements have one electron in the outside shell and they all have a valence of plus one. Group I elements will lose that one electron in the outside shell, to become a single positive ion with a full electron shell of eight electrons (an octet) in the s and p subshells under it
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tox terima cabaran...bagus
tp kalau artikel sendirik lebih baik...cam chewan bt kat ats tuh |
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eh nyahhh mak dh melupakan chem hokeyyyy.last taun 2004..tp iols dpt a+ hokeyyyy!!!!!!
toxicated Post at 20-1-2010 13:46 
ai dpt A- voley |
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ai nk tdo....good nite to me{:1_144:} |
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sedih sgt2..momod dauswq delate thread "radio Freq" iols.. |
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Category: Belia & Informasi
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Post time 20-1-2010 01:16 PM
Author
kt mana uni ker 
