Points to ponder:
- Group I (alkali metals) and group II (alkaline earth metals) are collectively called s- block elements with the general valence electronic configurations ns1 & ns2 respectively.
- There is a regular variation in their periodic properties. eg. Atomic and ionic radii decrease along the period and rest of the properties viz., electron gain enthalpy, ionization enthalpy and electronegativity increase along the period and the reverse trend is observed down the group.
- Lithium and Beryllium holds a diagonal relationship with Magnesium and Aluminium respectively. Most of their properties are similar.
- Important compounds of sodium includes sodium chloride, sodiumcarbonate (washing soda), sodium hydroxide and sodium hydrogen carbonate. The process involved in the manufacture of sodium hydroxide is Castner-Kellner process and that in the manufacture of sodium carbonate is solvay process.
- With slight deviations alkaline earth metals possess almost similar properties like alkali metals.
- Industrially important compounds of the essential element , calcium are Limestone(CaCO3), slaked lime(Ca(OH)2), quick lime(CaO) and Cement. Portlandland cement is important brand of cement which is manufactured with the help essential raw materials.Gypsum(CaSO4.2H2O) an other important compound of calcium is used in very small quantity in the cement industry for delaying the setting of cement. CaSO4.1/2 H2O commonly called as plaster of Paris is used for joining the fractured bones.
- Potassium, Sodium, Magnesium and Calcium are found in large portions as biological fluids as they are essential for performing the biological operations.