The Atoms Atoms are not achieved achieved the stable electron electron arrangement (duplet or octet) . Atom should donate, accept or share electron with other atoms to achieved stable electron arrangement and react react to form ionic ionic or covalent compound.
Electron arrangement of Heli Helium um : 2 du let let
Atom of noble gas achieved the stable electron arrangement (duplet or octet). They do no need to donate, accept or sharing electron with other atoms. Thus cannot react with other atoms. Why inert gases are stable?
Why atom of others elements are not 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 Metal (Group 1,2,13)
Non metal (Group 15,16,17)
Donate electron Positive ions (cation)
Non-metal atoms share electron to achieve stable octet electron arrangement
Accept electron
Attracted by strong electrostatic force
Pull together by Weak Van Der Waals forces
Negative ions anion Covalent compounds
Ionic compounds Conduct electricity in molten
High melting and boiling points
Not conduct electricit
Low melting points
Positive ion (cation)
Atom (Neutral)
Donate electron
Sodium ions , Na+ +
Chlorine atom, Cl
Sodium atom, Na
2.8.1
Charge of 11 protons = +11 Charge of 10 electrons = -10 Total charge = +1
2.8.7
Charge of 11 protons = +11 Charge of 11 electrons = -11 Total charge =0
Charge of 17 protons = +17 Charge of 17 electrons = -17 Total charge =0
Formation of Sodium Chloride Na 2.8.1
-
2.8.8 Charge of 17 protons = +17 Charge of 18 electrons = -18 Total charge = -1 Formation of Magnesium Chloride
Cl
NaCl Electron arrangement
2.8.7
Donate one electron
2.8
Chlorine atom, Cl -
accept electron
Donate electron
2.8
Negative ions (anion)
accept electron
Accept one electron
to achieve the stable octet electron
2.8
Draw the diagram of the formation of sodium chloride, NaCl +
-
Sodium ion, Na+ and chloride ion, Cl - are attracted to each other with strong attraction force to form sodium chloride
Atom Magnesium has 2 valence electron and atom Cl has 7 valence electron Electron arrangement of magnesium atom is 2.8.2 Magnesium atom donate two electron to two atom chlorine form magnesium ion, Mg2+ and achieve a stable octet electron arrangement. Mg Mg2+ + 2e Electron arrangement of Chlorine atom is 2.8.7 Each chlorine atom accept one electron from magnesium atom to form chloride ion, Cl - and achieve the stable octet electron arrangement. Cl + e ClThe magnesium ion, Mg2+ and chloride ion, Cl - are attracted to each other with strong attraction force to form ionic compound, Magnesium chloride MgCl 2 2+ -
