Atomic number: 13

Symbol: Al

Category: metal

Density at 25°C: solid,  2.70 g·cm−3

Ah aluminium or aluminum? doesn't really matter too much, just depends what region you are.  Well this is a pretty well know element being rather shiny and light. 

It's the first metal in the elements that actually holds its shine for a reasonable time too, but that is thanks to thin layer of aluminium oxide that forms on the surface.

Block of aluminium. image adapted from wikipedia

Use, natural applications or common combinations: 

  • Foil, also very recyclable 
  • Many engineering applications, for poles and structures
  • present in many minerals

Basic characteristics:

  • Standard atomic weight: 26.98
  • Melting point: 660.32 °C
  • Boiling point: 2519 °C
  • Radioactivity: almost all naturally stable
    • trace amounts of 26Al (radioactive isotope,half life of  7.2×105 y)