ANSWER:
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Metallic Bonding:
Metallic Bonding is restricted to metals only. In the metallic bonding, There is a electrostatic force of atrraction between the metal ions (which are positive)
and the electrons(which are negative).
The metal ions are arranged in a lattice pattern which is the regular repetitive structure.
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Electron Sea Level:
Every metal atom donate one or two valence electrons, so due to the BULK presence of the electrons, It results in a formation of sea of electrons. So the valence electrons don't just stay on their own atom, they roam around the whole metal. They are just like a sea of electrons. This is why it is called the electron sea model. basically metal ions are present as a iceberg or island in the freely floating sea of electrons.
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How is Sea of electron related to the malleable and ductile property?
The sea of electron works as a electron GLUE, That means the metal ions are strongly ATTRACTED to the electron, so When apply pressure on the metals they DONT BREAK that means they are not brittle but malleable and ductile. This is because of the moving electrons and because the cations slide easily past each other, The ability of the atoms to roll over each other into new positions without breaking the metallic bond is because of the electron glue.
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IMPORTANT STATEMENTS
Brittle; Hard but breakable due to absence of sea of electron.
Malleable and Ductile; Transformed into sheets and thin wires so they are somewhat ELASTIC.