Chemistry - Metals (Properties, extraction, and reactivity series)

Metals are elements that typically lose electrons to form positive ions (cations), such as $Na^+$ or $Mg^{2+}$.

Physical properties of metals include high melting and boiling points, malleability, ductility, and high thermal and electrical conductivity due to the presence of a 'sea' of delocalized electrons.

The reactivity series ranks metals from most to least reactive: $K > Na > Ca > Mg > Al > C > Zn > Fe > Sn > Pb > H > Cu > Ag > Au$.

A more reactive metal will displace a less reactive metal from its oxide or salt solution, e.g., $Mg(s) + CuSO_4(aq) \rightarrow MgSO_4(aq) + Cu(s)$.

Metals above carbon in the reactivity series (like $Al$) are extracted using electrolysis; metals below carbon (like $Fe$) are extracted by reduction with carbon or carbon monoxide.

Extraction of Iron occurs in a Blast Furnace where Haematite ($Fe_2O_3$) is reduced by carbon monoxide ($CO$).

Extraction of Aluminium involves the electrolysis of alumina ($Al_2O_3$) dissolved in molten cryolite ($Na_3AlF_6$) to lower the melting point and improve conductivity.

Alloys are mixtures of a metal with other elements. They are harder than pure metals because different-sized atoms disrupt the regular arrangement of the lattice, preventing layers from sliding over each other.