To understand this, we first need an overview of the basic theory of the structure of the atom , Conduction of electricity, conductors, and factors.

Atom is composed of three particles proton, neutron and electron.Electron is smallest particle of the three and is revolve around the nucleus, which contain proton and neutron.

Metal has three energy bands that is stated in band theory: valance band, band gap and conduction band.

When an electron gets enough energy, it jumps from the valance band to the conduction band then that electron started to contribute to electrical conductivity it also depends on the structure of the material.

What is Conductivity?

The conductivity is the ability to pass the current for example water has the ability to pass current, unlike honey. Or a material is said to be conductive if its electrons move freely in an atom.

Compare two materials: wood and copper. Which one do you think is a conductor and non-conductor?

Copper will conduct electrical current and wood will not as copper has more free electrons in material then wood.

Conductivity is measured in Siemen per meter(S/m) and is denoted by kappa‘k’ or sigma’ σ’.

What is Electric current?

The current which flows due to charges is called Electric current. There are two types of charges positive and negative charges. The current which flows due to positive charge is called Hole Current, Similarly, the current which flows due to negative charge is Electron Current.

Electric Current is measured in Ampere(A) and is denoted by capital letter ‘I’.

Conductor, Non-Conductor, and Semi-Conductor

A conductor which passes or conducts electricity is called conductor. For example, saltwater, copper, iron, brass, bronze, silver, gold are some conductors. In conductors, conduction band and valance band overlaps hence easing in conduction.

whereas non-conductors do not pass or conduct electricity they are also called insulators. Plastic, paper, glass, oil, ceramic, fabric are non-conductors/insulators. In non-conductors, valance and conduction band are at a certain distance, hence stopping the conduction.

Semiconductors are those which do not pass electricity on room temperature but only when energy is provided, common examples are Silicon and germanium. In semi-conductors, valance and conduction band are at a lesser distance than non-conductors hence hindering in conduction.

Conductivity in Silver

Silver is transition metal present in group 11, period 5 in the modern periodic table and have highest Electrical conductivity followed by gold .the reason is the Electronic configuration of Silver, the arrangement of electrons in an atom, it has 2,8,18,18,1 electron per shall, the last shell has one electron spare and loosely bonded with the nucleus, and is present in the conduction band, so it ended up contributing in conduction. Also, the size of an atom is also large. The lesser the influence of the nucleus on electron the more conductive material will be.

Some Factors Increasing Conductivity

Temperature: if we increase the temperature of metal its electron gets excited and started to jump from a low energy level to a high energy level thus increases the conduction.

Doping: Doping is usually done in semi-conductors in order to increase conductivity this is done by adding another impurity to increase electrons in the conduction band.

Amna Rizwan
Author

Amna being a Physicist wants to share her subject expertise and knowledge with people. Amna is a highly energetic and motivated lecturer as well.

5 Comments

  1. Avatar

    Very informative and knowledgable article. I really appreciate it.

  2. Avatar
    Imrana Faisal Reply

    Nicely explained terms and concepts. Love the presentation and sequence in which details are explained.

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