Cobalt: Element Overview
Basic Information
- Symbol: Co
- Atomic Number: 27
- Atomic Weight: 58.933194 u
- Element Category: Transition metal
- Group: 9
- Period: 4
Physical Properties
- Phase at Room Temperature: Solid
- Melting Point: 1495 °C (2723 °F)
- Boiling Point: 2927 °C (5301 °F)
- Density: 8.90 g/cm³ at 20 °C
- Color: Lustrous, silver-gray metal
- Crystal Structure: Hexagonal close-packed (hcp) at room temperature, face-centered cubic (fcc) at higher temperatures
Chemical Properties
- Electronegativity: 1.88 (Pauling scale)
- Ionization Energies:
- First: 760.4 kJ/mol
- Second: 1648 kJ/mol
- Third: 3232 kJ/mol
- Oxidation States: +2, +3 (most common), +1, +4
- Reactivity: Reacts slowly with oxygen and water; forms protective oxide layer.
Isotopes
- Stable Isotopes: Cobalt has one stable isotope: Co-59.
- Radioisotopes: The most notable radioisotope is Co-60, which is used in medical and industrial applications.
Occurrence and Production
- Natural Abundance: Cobalt is the 32nd most abundant element in the Earth’s crust.
- Sources: Found in minerals such as cobaltite (CoAsS), erythrite (Co₃(AsO₄)₂·8H₂O), and as a byproduct of nickel and copper mining.
- Production: Extracted by flotation processes followed by pyrometallurgical or hydrometallurgical techniques.
Uses and Applications
- Alloys: Used to make superalloys for jet engines and gas turbines due to its high-temperature strength and corrosion resistance.
- Batteries: Essential component in lithium-ion batteries.
- Magnets: Used in the production of strong permanent magnets like alnico and samarium-cobalt magnets.
- Catalysts: Used as a catalyst in the petroleum and chemical industries.
- Medical: Used in the production of orthopedic implants and in radiotherapy for cancer treatment (Co-60).
Safety and Precautions
- Reactivity: Relatively non-reactive but can react with acids.
- Handling: Cobalt dust and fumes should be handled with care to avoid inhalation and skin contact.
- Toxicity: Cobalt compounds can be toxic if ingested or inhaled in large quantities; prolonged exposure can lead to respiratory issues and skin sensitization.
Biological Role
- Essential Element: Cobalt is essential for humans as a component of vitamin B12 (cobalamin).
- Health: Required in trace amounts for red blood cell production and neurological function.
Historical Background
- Discovery: Known to ancient civilizations but identified as an element by Georg Brandt in 1735.
- Naming: Named after the German word “kobalt” or “kobold,” meaning goblin or evil spirit, due to the troublesome nature of its ores to miners.
Interesting Facts
- Cobalt Blue: A bright blue pigment made from cobalt compounds, historically significant in art and ceramics.
- Radiation Source: Cobalt-60 is a significant source of gamma rays used in medical treatments and sterilization.
- Space Exploration: Used in materials for spacecraft due to its durability and resistance to space environments.
Summary
Cobalt is a versatile transition metal known for its high-temperature strength, corrosion resistance, and essential role in biological systems. It is primarily extracted as a byproduct of nickel and copper mining and is used in superalloys, batteries, magnets, and medical applications. Discovered in the 18th century, cobalt continues to be a critical material in modern technology, from aerospace engineering to healthcare.
Questions and Answers about Cobalt:
Q: What is the chemical symbol for Cobalt?
- A: Co
Q: What is the atomic number of Cobalt?
- A: 27
Q: What type of element is Cobalt?
- A: Transition metal
Q: What is the atomic weight of Cobalt?
- A: 58.933194 u
Q: What group is Cobalt in?
- A: Group 9
Q: What period is Cobalt in?
- A: Period 4
Q: What is the phase of Cobalt at room temperature?
- A: Solid
Q: What is the melting point of Cobalt?
- A: 1495 °C (2723 °F)
Q: What is the boiling point of Cobalt?
- A: 2927 °C (5301 °F)
Q: What is the density of Cobalt at 20 °C?
- A: 8.90 g/cm³
Q: What is the color of Cobalt metal?
- A: Lustrous, silver-gray
Q: What is the crystal structure of Cobalt?
- A: Hexagonal close-packed (hcp) at room temperature, face-centered cubic (fcc) at higher temperatures
Q: What is the electronegativity of Cobalt?
- A: 1.88 (Pauling scale)
Q: What is the first ionization energy of Cobalt?
- A: 760.4 kJ/mol
Q: How many stable isotopes does Cobalt have?
- A: One (Co-59)
Q: What is the most notable radioisotope of Cobalt?
- A: Co-60
Q: How is Cobalt commercially produced?
- A: Extracted by flotation processes followed by pyrometallurgical or hydrometallurgical techniques
Q: What is the natural abundance of Cobalt in the Earth’s crust?
- A: 32nd most abundant element
Q: What common minerals contain Cobalt?
- A: Cobaltite (CoAsS), erythrite (Co₃(AsO₄)₂·8H₂O)
Q: What industry uses Cobalt extensively for superalloys?
- A: Aerospace industry
Q: What is one use of Cobalt in the battery industry?
- A: Essential component in lithium-ion batteries
Q: What role does Cobalt play in the production of magnets?
- A: Used in the production of strong permanent magnets like alnico and samarium-cobalt magnets
Q: Why is Cobalt used in the chemical industry?
- A: Used as a catalyst in various chemical reactions
Q: What is the biological role of Cobalt in the body?
- A: Component of vitamin B12, essential for red blood cell production and neurological function
Q: Who discovered Cobalt?
- A: Georg Brandt
Q: In what year was Cobalt discovered?
- A: 1735
Q: What is the origin of the name “Cobalt”?
- A: From the German word “kobalt” or “kobold,” meaning goblin or evil spirit
Q: What property makes Cobalt suitable for use in superalloys?
- A: High-temperature strength and corrosion resistance
Q: What health hazard is associated with prolonged exposure to Cobalt dust or fumes?
- A: Can cause respiratory issues and skin sensitization
Q: How should Cobalt and its compounds be handled?
- A: With care, using appropriate protective equipment to avoid inhalation and skin contact
Q: What is the second ionization energy of Cobalt?
- A: 1648 kJ/mol
Q: What is the third ionization energy of Cobalt?
- A: 3232 kJ/mol
Q: Is Cobalt essential for plant health?
- A: Not essential for most plants, but required by some microorganisms
Q: What is the significance of Cobalt in enzyme function?
- A: Acts as a cofactor in enzymatic reactions, particularly in vitamin B12
Q: What is the role of Cobalt in the production of orthopedic implants?
- A: Used due to its biocompatibility and strength
Q: How does Cobalt benefit the medical industry?
- A: Used in radiotherapy for cancer treatment and in the production of medical implants
Q: What is Cobalt’s role in improving battery technology?
- A: Enhances energy density and cycle life in lithium-ion batteries
Q: What is the use of Cobalt in pigments and dyes?
- A: Produces bright blue pigments like cobalt blue
Q: How does Cobalt contribute to space exploration?
- A: Used in materials for spacecraft due to its durability and resistance to space environments
Q: What color are Cobalt compounds typically?
- A: They can exhibit a variety of colors, with cobalt blue being particularly notable
