Significance

• Cesium is the most electropositive element in the periodic table, meaning it has the greatest ability to form positive ions. It is almost the most alkaline, or characterized by a low concentration of hydrogen ions.
  
  

Contact with Oxygen

• Cesium reacts very quickly in the presence of oxygen. As a result, chemists must store Cesium in an inert, dry environment or submerge it in oil or kerosene.
  
  

Contact with Water

• When Cesium comes in contact with water, it reacts violently; releasing hydrogen gas, which is highly flammable. Cesium reacts with ice at temperatures of 116 K (degrees Kelvin) or higher.
  
  

Ionization Potential

• First ionization potential refers to the energy required to take the outermost electron away from a neutral atom that is in a gaseous state; second ionization potential is the energy need to remove the second outermost electron. Expressed using the energy unit "electron volts," the first ionization potential of Cesium equals 3.894 eV, while its second ionization potential is 25.1 eV.
  
  

Electron Work Function

• The minimum amount of photonic energy needed to take an electron away from a solid and move it to the vacuum outside the solid is called electron work function. Cesium has an electron work function of 2.14eV.