Lead is a metal that conducts electricity. This is because it has freely moving electrons. However, its conductivity is low because it readily combines with atmospheric oxygen to become lead oxide.
This layer of oxide takes out the freely moving electrons in the naturally occurring metal. This eradication means electricity will not readily move through lead in the presence of a voltage potential.
To better understand the relationship between lead and electricity, this guide will walk you through how the metal conducts electricity in different states, its properties, structure, and electrical conductivity.
You will also learn about the metal’s ability to conduct heat (thermal conductivity) and its various real-life applications.
Properties and Structure of Lead
- Lead is a group 14 p block element with an atomic number of 82 and 4 valence electrons.
- The closely-packed face-centered cubic metal has a density of 11.34 g/cm3,
- Lead does not dissolve in hydrochloric acid or react readily with alkali.
- Lead is also malleable and ductile (but not enough to be ideal for electrical wire)
- The metal is obtained from heating mineral galena (PbS) in the presence of oxygen.
- It has a melting and boiling point of 327.5°C and 1740°C, respectively.
- Under normal conditions, it does not react with water and is resistant to corrosion.
- Lead dissolves in cold bases to form plumbates (a salt containing lead PbO32− and oxygen as the anion.
How Does Lead Conduct Electricity?
Lead conducts electricity because delocalized and freely moving electrons are present in its atoms. However, during its conduction, it also combines with atmospheric oxygen to form a layer of oxide.
2Pb + O2 ——–> 2PbO
This results in poor conduction of electricity in lead. At a very low temperature, lead can behave like a type I superconductor (especially when it is cooled below 7.2K).
Electrical Conductivity of Lead
Metals are natural conductors with varying electrical conductivity. This means they allow current to flow through them at varying capacities and under different conditions.
The electrical conductivity of lead is 4.55 x 106 at 20°C. The formula for calculating the electrical conductivity of any material is:
σ = l/RA
Where:
- σ = Electrical conductivity
- R = Resistance of the material
- A = Cross-sectional area of material
- L = Length of material
Electrical Resistivity of Lead
Electrical resistivity is the opposite of conductivity. It is a measure of resistance to the flow of electricity any material possesses. For context, lead has an electrical resistivity of 2.2 x 10-7 Ohm meter.
For calculating the electrical resistivity of any material is:
ρ = RA/l
Where:
- ρ = Resistivity
- R = Resistance of the material
- A = Cross-sectional area of material
- L = Length of material
Does Molten Lead Bromide Conduct?
Although lead bromide is an ionic compound, it does not conduct electricity in its solid state. This is because its ions are closely connected by electrostatic (covalent) forces.
Molten lead or molten lead bromide, on the other hand, conducts electricity. Under a potential, the compound splits into positively charged ions, or cations, and negatively charged ions, or anions.
Pb2+ ions gain electrons at the cathode to become Pb atoms, whereas Br- ions lose electrons at the anode to become Br atoms. These Br atoms eventually pair up to become Br2+ molecules.
Is Pencil Lead a Conductor of Electricity?
Pencil “lead” is a product of graphite and clay. Since graphite is an allotrope of carbon and makes up a large portion of the pencil line, pencil lead conducts electricity.
Does Lead Conduct Heat?
Lead is a poor conductor of heat. This is because it readily reacts with atmospheric oxygen. The thermal conductivity of lead is 34.7 W/mK
Uses of Lead
- Lead is used for roofing, designing water or pipes, and covering cables because it is corrosive-resistant, budget-friendly, and has a low melting point.
- It is also the chief component of lead accumulators, lead oxides, and lead (VI) tetraethyl.
- Thanks to its lightweight, lead feature in the manufacture of bullets, Pb shots (an essential vaccination for recruits in the army), and weights found in gyms.
- Lead is used in making alloys such as type metal, pewter, and plumber’s solder.
- It also serves as a protection against X-rays and other radioactive radiations. This is thanks to its high absorbing power and high density.
FAQs
Is lead a poor conductor of heat and electricity?
Lead is a poor conductor of heat and electricity. This is because it readily combines with the environment to form metal oxide.
Is lead a better conductor than copper?
Although lead can behave as a superconductor at certain temperatures, it is not a better conductor than copper.
Is lead useful to humans?
Pure lead is dangerous within the body’s system. However, outside the body, it contributes to manufacturing various applications like roofing and pipes.
Conclusion
It is safe to call pure lead a conductor of electricity. This conductivity reduces drastically when interacting with atmospheric oxygen, as the freely moving (delocalized) electrons are stable.
They act as superconductors at a temperature below 7.2 K (meaning they have zero or close to zero resistance). In a molten state, they are usually a combination of lead (Pb) and bromine (Br) and can conduct electricity.
This is because molten lead is an ionic compound that associates with Pb and Br atoms on the cathode and anode, respectively.
I hope you found this guide helpful. To compare lead’s conductivity with other metals, check out my guide on metals that conduct electricity.
Thanks for reading.