Sodium (Na) 
Due to the reactivity of pure sodium metal it is not found naturally in the metallic state; however, its a common element and often found as part of a everyday household chemicals, for example common table salt, e.g. NaCl- Sodium Chloride or NaOH- Sodium Hydroxide (a strong base used in a wide range of cleaning solutions).
Sodium metal can be purified from NaCl or NaOH using electrolysis, on the industrial process of sodium metal extraction a mix of NaCl and CaCl- Calcium Chloride are heated to the molten state and a DC current is passed through the melt using a series of electrodes. A mix of NaCl and CaCl is used as the addition of CaCl reduces the melting point of the NaCl and during the electrolysis process liquid sodium metal forms at the cathode and chlorine gas and the anode; since the density of sodium is less than the mix of sodium and calcium chloride the extracted sodium floats to the top of the electrolysis cell and graphite is typically used as the anode since reactive chlorine gas forms at this electrode and compatible materials must be used. Initially heat needs to be applied to melt the NaCl and CaCl mix as there is no significant electrical conductivity while these materials are in the solid state, but when molten the free electrons allow for current flow and the external heat source can be turned off as the flow of electrical current produces the heat needed to maintain a molten salt (or at least as there is enough current flowing through the molten salt).

Physical properties

Phase at STP  Solid
Melting point     370.944 K ​(97.794 °C, ​208.029 °F)
Boiling point     1156.090 K ​(882.940 °C, ​1621.292 °F)
Density (at STP)     0.968 g/cm3 (at STP)

Other Properties of Sodium Metal
Crystal Structure: BCC
Youngs Modulus ~10 GPa
Shear Modulus ~ 3.3 GPa

Properties of Sodium Chloride
Density 2.165 g/cm3
Melting point: 801 °C
Crystal structure: FCC
   
Properties of Sodium Hydroxide
Density 2.13 g/cm3
Melting point: 318 °C

The following videos show some chemistry experiments and demonstrations relating to Sodium and Sodium Hydroxide

This video shows the reactive nature of Sodium metal and Sodium Hydroxide