METALLIC BONDING Flashcards
Why do metals have high melting points? (1)
because they have giant structures. there is a strong attraction between the metal ions and the delocalised electrons making it difficult to separate.
why are metals strong? (1)
the delocalised electrons extend throughout the solid so there are no individual bonds to break.
what does ductile mean? (1)
they can be pulled into thin wires.
why are metals malleable and ductile? (2)
after a small distortion, each metal ion is still in exactly the same environment as before so the new shape is retained.
why are metals good conductors of electricity? (1)
the delocalised electrons that can move throughout the structure, an electron from the negative terminal of the supply joins the electron sea at other end of a metal while at the same time a different electron leaves the wire at the positive terminal.
how does the charge on the ion affect the strength on the metallic bond? (1)
the greater the charge on the ion, the greater the number of delocalised electrons and the stronger the electrostatic attraction between the positive ions and electrons.
how does the size of an ion affect the strength of a metallic bond? (1)
the smaller the ion, the closer the electrons are to the positive nucleus and the stronger the bond.
what does the strength of a metallic bond depend on? (2)
-the charge on the ion
-the size of the ion
why are metals good conductors of heat? (1)
they have high thermal conductivities, energy is spread through increasingly vigorous vibrations of the closely packed ions.
what does malleable mean? (1)
they can be beaten into shape.
what is metallic bonding? (1)
in a metal element, the outer main levels of the atoms merge therefore the outer electrons are no longer associated with any particular atom.
what does delocalised mean? (1)
when electrons are not tied to a particular atom.
what are the properties of metals? (4)
-good conductors of heat and electricity
-strength of metal
-malleable and ductile
-high melting points
what happens in metallic bonding? (2)
the positive ions tend to repel each other and this is balanced by the electrostatic attraction of thee positive ions for the negatively charged ‘sea’ of delocalised electrons.
what is the structure of metallic bonding? (1)
metals consist of a lattice of positive ions existing in a ‘sea’ of outer electrons ‘delocalised’
