The document discusses the electron configuration of noble gases and other elements. It explains that noble gases achieve a stable electron configuration of either a duplet or octet, while other elements must bond with each other to reach stability by donating, accepting, or sharing electrons. This bonding can occur through ionic bonds, where electrons are transferred, or covalent bonds, where electrons are shared. Ionic bonding results in the formation of ionic compounds between metals and nonmetals, while covalent bonding forms covalent compounds between nonmetals.

1. Electron arrangement of Electron arrangement
neon : 2.8 (octet) of Helium : 2 (duplet)
The Atoms are not achieved the stable electron Atom of noble gas achieved the stable electron
arrangement (duplet or octet) . arrangement (duplet or octet).
Atom should donate, accept or share electron with They do no need to donate, accept or sharing
other atoms to achieved stable electron electron with other atoms. Thus cannot react with
arrangement and react to form ionic or covalent other atoms.
compound.
Why atom of others Why inert gases are
elements are not stable? stable?
FORMATION OF
COMPOUNDS
CHEMICAL BONDS
IONIC BONDS COVALENTL BONDS
Formed through Formed through
Formed by sharing of electrons between non-metals
Formed by transfer of
electrons from metal atom to
non-metal
Non-metal atoms share electron to achieve stable octet
Metal electron arrangement
(Group 1,2,13) Non metal
(Group 15,16,17)
Donate electron Accept electron Pull together by
Attracted by strong Weak Van Der Waals forces
Positive ions
electrostatic force Negative ions
(cation)
(anion)
Covalent compounds
Ionic compounds
Conduct electricity High melting and Not conduct Low melting points
in molten boiling points electricity

2. Positive ion (cation) Atom Negative ions (anion)
Donate electron accept electron
(Neutral)
Sodium ions , Na+ Sodium atom, Na Chlorine atom, Cl Chlorine atom, Cl-
-
+
accept electron
Donate electron
2.8 2.8.1 2.8.7 2.8.8
Charge of 11 protons = +11 Charge of 11 protons = +11 Charge of 17 protons = +17 Charge of 17 protons = +17
Charge of 10 electrons = -10 Charge of 11 electrons = -11 Charge of 17 electrons = -17 Charge of 18 electrons = -18
Total charge = +1 Total charge =0 Total charge =0 Total charge = -1
Formation of Sodium Chloride Formation of Magnesium Chloride
Na NaCl Cl Atom Magnesium has 2 valence electron and atom Cl has 7
valence electron
2.8.1 Electron arrangement 2.8.7 Electron arrangement of magnesium atom is 2.8.2
Magnesium atom donate two electron to two atom chlorine
Donate one electron Accept one electron form magnesium ion, Mg2+ and achieve a stable octet electron
to achieve the stable arrangement.
2.8 octet electron 2.8 Mg Mg2+ + 2e
arrangement
Electron arrangement of Chlorine atom is 2.8.7
Draw the diagram of the formation of sodium chloride, NaCl Each chlorine atom accept one electron from magnesium atom
+ to form chloride ion, Cl- and achieve the stable octet electron
-
arrangement.
Cl + e Cl-
The magnesium ion, Mg2+ and chloride ion, Cl- are attracted to
each other with strong attraction force to form ionic
compound, Magnesium chloride MgCl2
- 2+ -
Sodium ion, Na+ and chloride ion, Cl- are attracted to each
other with strong attraction force to form sodium chloride
compound, NaCl