- Atomic Number: 82
- Atomic Weight: 207
- Melting Point: 327.5 °C (621.43 °F)
- Boiling Point: 1749 °C (3180 °F)
- Discovered by: Known to humans since ancient times
Lead is the densest chemical element of all the non-radioactive ones. It is a soft metal having an atomic number of 82, after which in the periodic table, radioactive heavy metals start. The symbol of lead is ‘Pb’, which has been derived from the Latin word ‘plumbum’. Lead is a very useful metal which is utilised in car batteries.
Characteristics and Properties
Lead is a stable heavy and post-transition metal.Its common isotope is non-radioactive. Mostly, lead is an end product of heavy metals,which is produced after their decay in a particular series.
A few more properties of lead are as follows:
- Dark silver in colour
- Resistant to corrosion
- Moderately reactive
- Changesinto dull grey colour in air
Lead is one of the useful metals widely used in a number of products. Nowadays, lead in general is utilised in lead-acid batteries which are used in the homes for power back-up and in cars. A soft and low temperature melting alloy is also made by mixing it with tin. Joining of electrical connections and component on circuit boards is done using this alloy.
Besides being a very useful element, lead is also a very toxic and harmful substance for the health of human beings. In the human body, lead can be absorbed if it gets in contact with skin or if consumed in any form. It results in lead poisoning,which causes nervous system damage and problems in heart, intestines and kidneys.
A few more uses of lead are as follows:
- Lead is utilised to compensate weights for scuba divers.
- It is used in making different pigments, and in ammunition to rise their weight-to-volume ratio.
- For blocking nuclear radiations, it is used as a protective layer.
Where is it found?
Lead is a moderately reactive element,which is generally not found in its elemental form. It has been given the 38th number in the list of abundant elements. It is mostly found with sulphur and in a number of naturally found minerals. Anglesite (PbSO4), galena (PbS) and boulangerite are the minerals, in which most of the lead is obtained.
Though lead is found in a number of countries,yet Australia, China and the USA are the largest producers of lead. The total production of lead is more than 8 million tons per year, in which 40-50% is recycled from waste materials.
Lead is one of those metals,which human beings were aware of since ancient times. Because of its lower melting point and high malleability, it was a very useful metal for people of that time. It is the Romans who have used lead metal to prepare the pipes which are used to pump the water to the cities and their houses. But these days,using lead for that purpose is not considered good on account of lead poisoning.
- People were confused with lead and tin in ancient times. People of that time considered them as the same element with a different form. Tin was referred to as white lead, whereas the actual lead metal was referred to as black lead.
- Today, it is the lead-acid batteries, which most of the recycled lead comes from.
- According to the archaeological facts, people of ancient Greece and China were well aware of lead poisoning.
- Lead is the only metal which shows zero Thomson effect. That is, when an electrical current is passed through a sample of lead, heat is neither absorbed nor produced.