Bromine: Element Overview
Basic Information
- Symbol: Br
- Atomic Number: 35
- Atomic Weight: 79.904 u
- Element Category: Halogen
- Group: 17
- Period: 4
Physical Properties
- Phase at Room Temperature: Liquid
- Melting Point: -7.2 °C (19.0 °F)
- Boiling Point: 58.8 °C (137.8 °F)
- Density: 3.1028 g/cm³ at 20 °C
- Color: Reddish-brown
- Odor: Pungent and irritating
- Crystal Structure: Orthorhombic (when solid)
Chemical Properties
- Electronegativity: 2.96 (Pauling scale)
- Ionization Energies:
- First: 1139.9 kJ/mol
- Second: 2103 kJ/mol
- Third: 3470 kJ/mol
- Oxidation States: -1, +1, +3, +4, +5 (most common is -1)
- Reactivity: Highly reactive and forms compounds with many elements.
Isotopes
- Stable Isotopes: Bromine has two stable isotopes: Br-79 and Br-81.
- Br-79: 50.69%
- Br-81: 49.31%
- Radioisotopes: Several radioisotopes, including Br-82, which is used in some medical applications.
Occurrence and Production
- Natural Abundance: Bromine is the 64th most abundant element in the Earth’s crust.
- Sources: Found in seawater as bromide ions (Br⁻) and in minerals such as bromargyrite (AgBr) and carnallite (KMgCl₃·6H₂O).
- Production: Extracted from brine pools, seawater, and natural brine deposits through a series of chemical reactions and distillation processes.
Uses and Applications
- Flame Retardants: Used in the production of brominated flame retardants.
- Pesticides: Used in fumigants and pesticides.
- Pharmaceuticals: Used in the synthesis of various pharmaceuticals and medicinal compounds.
- Water Treatment: Used as a disinfectant in swimming pools and spas.
- Photography: Silver bromide (AgBr) is used in photographic films and papers.
- Organic Synthesis: Used in organic chemistry for bromination reactions.
Safety and Precautions
- Reactivity: Bromine is highly reactive and corrosive.
- Handling: Should be handled with extreme care, using appropriate protective equipment (gloves, goggles, and lab coats).
- Toxicity: Bromine is highly toxic and can cause severe burns on skin contact, respiratory distress if inhaled, and is harmful if ingested.
- Regulations: Strict regulations govern the handling and disposal of bromine due to its hazardous nature.
Biological Role
- Non-essential Element: Bromine is not essential for life but is found in trace amounts in human tissues.
- Health Effects: Exposure to bromine can lead to a range of health issues, including respiratory problems, skin irritation, and potential long-term effects on the nervous system.
Historical Background
- Discovery: Discovered by Antoine Jérôme Balard in 1826 in France.
- Naming: Named after the Greek word “bromos,” meaning stench, due to its strong, unpleasant odor.
Interesting Facts
- Unique State: Bromine is the only nonmetallic element that is liquid at room temperature.
- Color and Odor: Bromine’s reddish-brown color and strong odor make it easily identifiable.
- Volatility: Bromine is highly volatile, readily evaporating to form a reddish vapor.
Summary
Bromine is a highly reactive, reddish-brown liquid halogen with a pungent odor. It is used in various industrial applications, including flame retardants, pesticides, pharmaceuticals, water treatment, and photography. Discovered in the early 19th century, bromine is primarily extracted from brine pools and seawater. While it is not essential for biological processes, bromine is toxic and must be handled with extreme care. Its unique properties make it valuable in many chemical and industrial processes.
Questions and Answers about Bromine:
Q: What is the chemical symbol for Bromine?
- A: Br
Q: What is the atomic number of Bromine?
- A: 35
Q: What type of element is Bromine?
- A: Halogen
Q: What is the atomic weight of Bromine?
- A: 79.904 u
Q: What group is Bromine in?
- A: Group 17
Q: What period is Bromine in?
- A: Period 4
Q: What is the phase of Bromine at room temperature?
- A: Liquid
Q: What is the melting point of Bromine?
- A: -7.2 °C (19.0 °F)
Q: What is the boiling point of Bromine?
- A: 58.8 °C (137.8 °F)
Q: What is the density of Bromine at 20 °C?
- A: 3.1028 g/cm³
Q: What is the color of Bromine in its most stable form?
- A: Reddish-brown
Q: What is the crystal structure of Bromine when solid?
- A: Orthorhombic
Q: What is the electronegativity of Bromine?
- A: 2.96 (Pauling scale)
Q: What is the first ionization energy of Bromine?
- A: 1139.9 kJ/mol
Q: How many stable isotopes does Bromine have?
- A: Two (Br-79, Br-81)
Q: What is the most abundant isotope of Bromine?
- A: Br-79
Q: How is Bromine commercially produced?
- A: Extracted from brine pools, seawater, and natural brine deposits through a series of chemical reactions and distillation processes
Q: What is the natural abundance of Bromine in the Earth’s crust?
- A: 64th most abundant element
Q: What common minerals contain Bromine?
- A: Bromargyrite (AgBr), carnallite (KMgCl₃·6H₂O)
Q: What industry uses Bromine extensively for flame retardants?
- A: Chemical industry
Q: What is one use of Bromine in water treatment?
- A: Used as a disinfectant in swimming pools and spas
Q: What role does Bromine play in photography?
- A: Silver bromide (AgBr) is used in photographic films and papers
Q: Why is Bromine used in organic synthesis?
- A: Used for bromination reactions in organic chemistry
Q: What is the biological role of Bromine in the body?
- A: Bromine is not essential for life but is found in trace amounts in human tissues
Q: Who discovered Bromine?
- A: Antoine Jérôme Balard
Q: In what year was Bromine discovered?
- A: 1826
Q: What is the origin of the name “Bromine”?
- A: From the Greek word “bromos,” meaning stench
Q: What property makes Bromine unique among nonmetals?
- A: It is the only nonmetallic element that is liquid at room temperature
Q: What health hazard is associated with Bromine exposure?
- A: Can cause severe burns on skin contact, respiratory distress if inhaled, and is harmful if ingested
Q: How should Bromine and its compounds be handled?
- A: With extreme care, using appropriate protective equipment (gloves, goggles, and lab coats)
Q: What is the second ionization energy of Bromine?
- A: 2103 kJ/mol
Q: What is the third ionization energy of Bromine?
- A: 3470 kJ/mol
Q: Is Bromine essential for plant health?
- A: Bromine is not essential for plant health
Q: What is the significance of Bromine in flame retardants?
- A: Used in the production of brominated flame retardants
Q: What is the role of Bromine in the synthesis of pharmaceuticals?
- A: Used in the synthesis of various pharmaceuticals and medicinal compounds
Q: How does Bromine benefit the pesticide industry?
- A: Used in fumigants and pesticides
Q: What is Bromine’s role in industrial radiography?
- A: Radioisotope Br-82 is used in some medical applications
Q: What is the environmental impact of Bromine extraction?
- A: Can cause environmental contamination if not managed properly
Q: What color are Bromine compounds typically?
- A: They can exhibit various colors, often based on the oxidation state
Q: What is Bromine’s role in the nervous system?
- A: Exposure can lead to potential long-term effects on the nervous system
