Valancy

Introduction

We generally hear about metals and use them in day to day life. Do you exactly know what are metals? The naturally occurring minerals or substances from the earth’s crust are called metals. These are generally found in the form of metal ores, or combined with many other metals. They are also naturally present in the rocks washed by surface water and groundwater and in atmospheric dust. Some common examples are copper, aluminum, gold, silver, iron, sodium, calcium, etc. 

Metals are found everywhere around us. In fact, some of them are present within our body. Metals like sodium, calcium, potassium, iron form the major components of the human body.

 Physical Properties

  • Shiny and lustrous
  • Malleable
  • Ductile
  • Sonorous in nature
  • Good conductors of heat and electricity

Chemical properties

  • Only highly reactive metals react with water
  • They produce hydrogen gas when reacted with acids
  • They produce metal salts and  hydrogen gas when reacted with a base
  • Metal oxides are produced when reacted in the presence of oxygen

Applications

  • These are used in industries and factories containing huge pieces of equipment
  • Used in electronics for building up of transformers, capacitors and other microchips
  • Medicinal and pharmaceutical companies take up the major charge of metals for the production of drugs and medicines
  • Used in the manufacture of automobiles
  • Used in making precious jewelry
  • Used in making window panes and handles of the door
  • Used in oil refer refractory machines for the extraction of oil

Valency

The combining capacity of an atom or molecule is called valency. In other words, it is also referred to as the number of electrons lost or gained to attain a stable electronic configuration.  The electrons present in the outermost orbit of an atom are called valence Electrons. 

How to find the valency of an element

According to the Bohr-bury scheme, we come to know that the outermost shell contains a maximum of 8 electrons. Only a small amount of chemical reaction is observed when the outermost shell is completely filled. In other words, it is assumed that the combining capacity is zero. 

The ways on how to find valency of elements are given below:

Octet rule: The octet rule states that an atom is said to be stable if it contains 8 electrons in the outermost shell.  If the number of electrons present in the outermost shell lies in between one and four then the atom will have a positive valency. If the atoms are containing electrons in the outermost shell are higher than four then valency is determined by subtracting the number of electrons from eight. Except for Helium, all the noble gases have eight valence electrons.

Periodic table: The table consists of elements in such a manner that, the valency of a given element can be determined. Metals in column 1 have a valency of +1 while the noble gases in column 18 have a valency of 0 and are inert. In the periodic table, the elements in the same group have the same valency.

Valency from the chemical formula: On the basis of octet rule and by observing the combining of an element, the valency can be determined.