Lead is a metal that is really useful for different industries and human activities, however, it is also very toxic, which is why its uses and applications have been gradually replaced by other elements and metals.
| Symbol | Pb |
| Atomic number | 82 |
| Atomic mass | 207,2 |
| Discovered by | In the Middle East (7000 BC) |
Due to its physical and chemical properties, lead has endless applications that are friendly to the industry, because it is malleable and resistant to corrosion, but its particles cause many secondary effects on human health.
Important facts to know about lead
This metal is characterized by being a very bright chemical element, usually presenting itself with a bluish-white color.
Regarding its occurrence in nature and in the earth’s crust, it represents only 0.0013%, but this does not mean that it is rare, on the contrary, it is quite common to find it associated with minerals such as galena, anglesite and cerussite.
The chemical symbol for lead is Pb, which comes from the Latin word plumbum, meaning “waterworks,” referring to ancient times when the metal was widely used in the construction of water pipes.
Although there are 27 isotopes of lead, only four are considered stable.
diagnostic properties
| Chemical formula | Pb (native metal) |
| Color | Grey, but often overlaid with white hydrocerussite or related phases |
| luster or shine | metal |
| Mohs hardness | 1.5 |
| Density or specific weight | 11.37g/cm3 |
| crystalline system | isometric |
| Transparency | Opaque |
| stripe color | Gray |
| Tenacity | Malleable |
| cleavage | None |
| Fracture | Rough |
| Associated minerals | Galena, cerussite, anglesite |
Where is lead found?
Lead is primarily associated with lead sulfides such as galena, cerussite, and anglesite, which are typically mined from exhalative, Mississippi Valley, and volcanogenic massive sulfide (VMS) deposits. These deposits are rich in sulfides and lead.
It also appears in veinlets and asicate epithymal gold deposits and porphyry copper veinlets.
Lead properties and characteristics
- Atomic number (number of protons in the nucleus): 82
- Atomic symbol (in the periodic table of the elements): Pb
- Atomic weight (average mass of the atom): 207.2
- Density: 11,342 grams per cubic centimeter
- Phase at room temperature: solid
- Melting point: 621.4 degrees Fahrenheit (327.46 degrees Celsius)
- Boiling point: 3,180.2 degrees Fahrenheit (1,749 degrees Celsius)
- Number of isotopes (atoms of the same element with a different number of neutrons): 27.4 stable
- Most common isotopes: Pb-208 (52.4 percent of natural abundance);Pb-206 (24.1 percent of natural abundance);Pb-207 (22.1 percent of natural abundance);Pb-204 (1.4 percent of natural abundance natural)
1. Physical properties of lead
| Color | Bluish white |
| Malleability | Able to be molded or bent |
| Conductivity | Poor transmission of heat or electricity. |
| Softness | relatively smooth |
| Tensile | It can be stretched without breaking. |
| Gloss | a glow or glow |
| crystal structure | Face-Centered Cubic Crystal Structure |
Lead is a heavy metal of a greyish-bluish color with a slightly ferrous texture and it does not have a characteristic odor. Despite being a metallic element, it is very soft and ductile.
Lead is in the solid state and has a density of 11340 kg/m³.
At 1749 °C it reaches its boiling point, while its melting point is at 327 °C.
| Physical Properties | Metric | Imperial |
|---|---|---|
| Density (@20°C / 68°F) | 11.34g/cm3 | 0.409 lb/in3 |
| Melting point | 327°C | 621°F |
| Boiling point | 1755°C | 3191°F |
| Mechanical properties | Metric | Imperial |
|---|---|---|
| tensile strength | 18MPa | 2610psi |
| Poisson’s ratio | 0.42 | 0.42 |
| modulus of elasticity | 14 GPa | 2030 ksi |
| cutting module | 4.90 GPa | 711 ksi |
| Hardness, Brinell | 4.2 | 4.2 |
| Hardness, Vickers | 5 | 5 |
2. Chemical properties of lead
| Chemical formula | bp |
| reactivity with water | It dissolves slowly in water. |
| Oxidation | It does not readily react with oxygen in the air. |
| Inflammability | noburn |
| Reactivity with acids | It reacts quickly with hot acids but slowly with cold acids. |
| Corrosion | Highly resistant to corrosion but tarnishes on exposure to air. |
| Toxicity | Toxic |
Atomically, this metal is made up of 82 protons and electrons, in addition to 126 neutrons.
The Lead has an approved resistance to hydrochloric acid and sulfuric acid, while when it comes into contact with nitric acid and nitrogenous bases it tends to dissolve.
Lead is amphoteric, as it reacts with acids to form lead salts.
The most common oxidation state of lead is +2, but it is also common to use +4.
| CAS number | 7439-92-1 |
| Thermal Neutron Cross Section | 0.17 barns/atom |
| electrode potential | -0.126V |
| ionic radius | 0.840 Å |
| electronegativity | 1.8 |
| X-ray absorption edge | 0.14077 Å |
| electrochemical equivalent | 3.858g/A/h |
3. Where it comes from and how it is extracted
Lead is abundant in the earth’s crust, but It does not occur in its pure state but as lead sulphide.
It is obtained by mining extraction in rich lead deposits. The mineral that has the highest content of this metal is galena, but there is also another variety known as galena argentifera that can contain large amounts of silver.
Refining consists of extracting the lead particles from the pieces of ore, when the ore is calcined.
In this procedure, the lead is separated from the other elements. When obtaining a molten mass, it is poured into a reverberator accompanied by sulfur, steam and air.
4. In which part of the planet does it abound?
Lead is an element that can be found in the soil, water, air, plants, animals and volcanic emissions.
Lead is located in position 36 among the elements with the greatest abundance.
It is very common that it is accompanied by silver, gold, bismuth, zinc, antimony and sulfur. It is also frequent together with uranium and thorium, which are elements of a radioactive nature.
5. Functions in the human body
just the lead It does not fulfill any type of function in the organism, rather it has very harmful effects.
Among the damage caused is the decrease in the percentage of male fertility due to sperm damage, alteration in the behavior of children and the progressive decrease in learning abilities, increased blood pressure and liver damage, among many others.
Much of the food has a certain amount of this metal in its composition.
6. Benefits in technology
Lead was extremely useful at an industrial level, but its use has decreased because it is harmful.
Its usefulness was widely recognized in the manufacture of pipes and metal parts for the home, but it was replaced by other metals that do not put people’s health at risk.
However, this metal found its place in the nuclear sciences where It is used to make containers for dumping radioactive material. and other dangerous chemicals.
This unique use of due to its great resistance and density, in addition to its remarkable ability to contain ionizing radiation in a certain way.
7. Benefits in society
This metal has been accompanying man since the earliest times of life, however, in the modern era its common use was minimized.
But even this metal does not lose its full validity, its use is decisive in the telecommunications industry and in the metallurgical field.
8. Lead alloys
Lead is widely used in the metallurgical industry, because it participates in alloys with metallic elements such as cadmium, antiminum, sodium, copper, bismuth, tin and arsenic.
The small amounts of arsenic, antimony, copper and other metals will add more hardness, which add to its great resistance to atmospheric corrosion and attack by acids.
9. Lead toxicity
Lead is a very heavy metal, which is why it is very harmful to health.
Prolonged exposure to this element can generate a pathology known as plumbosis which can be fatal.
10. Use in telecommunications
Lead was replaced in many areas, but one of its special uses is still in force, as is its application in covers for the protection of wiring for television, internet, telephone lines and electricity.
11. Lead and the environment
According to the North American public health authorities, the level of lead in the environment has increased by more than 100% in the last century. This thanks to the various activities of humanity. The big increase occurred between 1950 and 2000 when gasoline became more widely used with lead globally.
Now, during that period, the US government established federal regulations and made recommendations. All this to limit the emissions of lead and protect public health in the United States and worldwide. And it should be noted that high lead emissions commonly occur in mineral deposits along with other metals such as copper and zinc.
These regulations are intended to protect people’s health because this metal has been purchased is toxic.