02-05-2021

Bromine Mass Number



Atomic mass of Bromine is 79.904 u. Note that, each element may contain more isotopes, therefore this resulting atomic mass is calculated from naturally-occuring isotopes and their abundance. The unit of measure for mass is the atomic mass unit (amu). One atomic mass unit is equal to 1.66 x 10 -24 grams. Do a quick conversion: 1 moles Bromine = 79.904 gram using the molecular weight calculator and the molar mass of Br. Check the chart for more details. Exact Mass: 80.92635 g/mol: Computed by PubChem 2.1 (PubChem release 2019.06.18) Monoisotopic Mass: 80.92635 g/mol: Computed by PubChem 2.1 (PubChem release 2019.06.18) Topological Polar Surface Area: 0 Ų: Computed by Cactvs 3.4.6.11 (PubChem release 2019.06.18) Heavy Atom Count: 1: Computed by PubChem: Formal Charge: 0: Computed by PubChem. Bromine Br Element 35 Mass Number: 80 Atomic weight: 79.904 g/mol Atomic number (Z): 35 Electrons: 35 Protons: 35 Neutrons: 45 Period: 4 Group: 17 Block: p.

The Mass Spectrometer

In order to measure the characteristics of individual molecules, a mass spectrometer converts them to ions so that they can be moved about and manipulated by external electric and magnetic fields. The three essential functions of a mass spectrometer, and the associated components, are:

  1. A small sample is ionized, usually to cations by loss of an electron. The Ion Source
  2. The ions are sorted and separated according to their mass and charge. The Mass Analyzer
  3. The separated ions are then measured, and the results displayed on a chart. The Detector

Because ions are very reactive and short-lived, their formation and manipulation must be conducted in a vacuum. Atmospheric pressure is around 760 torr (mm of mercury). The pressure under which ions may be handled is roughly 10-5 to 10-8 torr (less than a billionth of an atmosphere). Each of the three tasks listed above may be accomplished in different ways. In one common procedure, ionization is effected by a high energy beam of electrons, and ion separation is achieved by accelerating and focusing the ions in a beam, which is then bent by an external magnetic field. The ions are then detected electronically and the resulting information is stored and analyzed in a computer. A mass spectrometer operating in this fashion is outlined in the following diagram. The heart of the spectrometer is the ion source. Here molecules of the sample (black dots) are bombarded by electrons (light blue lines) issuing from a heated filament. This is called an EI (electron-impact) source. Gases and volatile liquid samples are allowed to leak into the ion source from a reservoir (as shown). Non-volatile solids and liquids may be introduced directly. Cations formed by the electron bombardment (red dots) are pushed away by a charged repellor plate (anions are attracted to it), and accelerated toward other electrodes, having slits through which the ions pass as a beam. Some of these ions fragment into smaller cations and neutral fragments. A perpendicular magnetic field deflects the ion beam in an arc whose radius is inversely proportional to the mass of each ion. Lighter ions are deflected more than heavier ions. By varying the strength of the magnetic field, ions of different mass can be focused progressively on a detector fixed at the end of a curved tube (also under a high vacuum).

When a high energy electron collides with a molecule it often ionizes it by knocking away one of the molecular electrons (either bonding or non-bonding). This leaves behind a molecular ion (colored red in the following diagram). Residual energy from the collision may cause the molecular ion to fragment into neutral pieces (colored green) and smaller fragment ions (colored pink and orange). The molecular ion is a radical cation, but the fragment ions may either be radical cations (pink) or carbocations (orange), depending on the nature of the neutral fragment. An animated display of this ionization process will appear if you click on the ion source of the mass spectrometer diagram.

Element Bromine - Br

Comprehensive data on the chemical element Bromine is provided on this page; including scores of properties, element names in many languages, most known nuclides of Bromine. Common chemical compounds are also provided for many elements. In addition technical terms are linked to their definitions and the menu contains links to related articles that are a great aid in one's studies.

Bromine Menu

  • Bromine Page One
  • Bromine Page Two
  • Bromine Page Three
MolarBromine

Overview of Bromine

  • Atomic Number: 35
  • Group: 17
  • Period: 4
  • Series: Halogens

Bromine's Name in Other Languages

  • Latin: Bromum
  • Czech: Brom
  • Croatian: Brom
  • French: Brome
  • German: Brom - r
  • Italian: Bromo
  • Norwegian: Brom
  • Portuguese: Bromo
  • Russian: Бром
  • Spanish: Bromo
  • Swedish: Brom

Atomic Structure of Bromine

  • Atomic Radius: 1.12Å
  • Atomic Volume: 23.5cm3/mol
  • Covalent Radius: 1.14Å
  • Cross Section (Thermal Neutron Capture)σa/barns: 6.8
  • Crystal Structure: Orthorhombic
  • Electron Configuration:
    1s2 2s2p6 3s2p6d10 4s2p5
  • Electrons per Energy Level: 2,8,18,7
    Shell Model
  • Ionic Radius: 1.96Å
  • Filling Orbital: 4p5
  • Number of Electrons (with no charge): 35
  • Number of Neutrons (most common/stable nuclide): 45
  • Number of Protons: 35
  • Oxidation States:±1,5
  • Valence Electrons: 4s2p5
    Electron Dot Model

Chemical Properties of Bromine

  • Electrochemical Equivalent: 2.9812g/amp-hr
  • Electron Work Function:
  • Electronegativity: 2.96 (Pauling); 2.74 (Allrod Rochow)
  • Heat of Fusion: 5.286kJ/mol
  • Incompatibilities:
    combustible organics (sawdust, wood, cotton, straw, etc.), oxidizable material, aqueous ammonia, hydrogen, acetylene, phosphorus, aluminum, titanium, mercury, potassium, other metals.
  • Ionization Potential
    • First: 11.814
    • Second: 21.8
    • Third: 36
  • Valence Electron Potential (-eV): -7.35

Physical Properties of Bromine

  • Atomic Mass Average: 79.904
  • Boiling Point: 332.4K 59.25°C 138.65°F
  • Coefficient of lineal thermal expansion/K-1: N/A
  • Conductivity
    Electrical:
    Thermal: 0.00122 W/cmK
  • Density: 3.119g/cc @ 300K
  • Description:
    Heavy, red-brown, fuming liquid with a choking, irritating odor; causes tears
  • Elastic Modulus:
    • Bulk: 1.9/GPa
  • Enthalpy of Atomization: 111.7 kJ/mole @ 25°C
  • Enthalpy of Fusion: 5.29 kJ/mole
  • Enthalpy of Vaporization: 15.46 kJ/mole
  • Flammablity Class: Noncombustible Liquid
  • Freezing Point:see melting point
  • Heat of Vaporization: 15.438kJ/mol
  • Melting Point: 266.05K -7.1°C 19.2°F
  • Molar Volume: 25.62 cm3/mole
  • Optical Refractive Index: 1.001132
  • Physical State (at 20°C & 1atm): Liquid
  • Realitive Gas Density (Air=1) = 5.51
  • Specific Heat: 0.473J/gK
  • Vapor Pressure = 5800Pa@-7.1°C

Regulatory / Health

  • CAS Number
    • 7726-95-6
  • UN/NA ID and ERG Guide Number
    • 1744 / 154
  • RTECS: EF9100000
  • NFPA 704
    • Health: 4
    • Fire:
    • Reactivity:
    • Special Hazard:
  • OSHAPermissible Exposure Limit (PEL)
    • 1 ppm = 6.54mg/m3 @ 25°C & 1 atm
    • TWA: 0.1 ppm
  • OSHA PEL Vacated 1989
    • TWA: 0.1 ppm
    • STEL: 0.3 ppm
  • NIOSHRecommended Exposure Limit (REL)
    • TWA: 0.1 ppm
    • STEL: 0.3 ppm
    • IDLH: 3 ppm
  • Routes of Exposure: Inhalation; Ingestion; Skin and/or eye contact
  • Target Organs: Respiratory system, eyes, central nervous system, skin
  • Levels In Humans:
    Note: this data represents naturally occuring levels of elements in the typical human, it DOES NOT represent recommended daily allowances.
    • Blood/mg dm-3: 4.7
    • Bone/p.p.m: 6.7
    • Liver/p.p.m: 0.2-7
    • Muscle/p.p.m: 7.7
    • Daily Dietary Intake: 0.8-24 mg
    • Total Mass In Avg. 70kg human: 260 mg

Who / Where / When / How

  • Discoverer: Antoine J. Balard/ C. Löwig
  • Discovery Location: Montpellier France/Heidelberg Germany
  • Discovery Year: 1826
  • Name Origin:
    Greek: brômos (stench).
  • Abundance of Bromine:
    • Earth's Crust/p.p.m.: 0.37
    • Seawater/p.p.m.: 65
    • Atmosphere/p.p.m.: N/A
    • Sun (Relative to H=1E12): N/A
  • Sources of Bromine:
    Occurs in compounds in sea water, Dead Sea, natural brines and salt-lake evaporates. World wide production estimated to be around 330,000 tons per year. Main mining areas are USA, Israel, UK, Russia, France and Japan.
  • Uses of Bromine:
    Used for water purification (swimming pools), manufacture of ethylene dibromide (anti-knocking gasoline), bleaching, organic synthesis, solvent, analytical reagent, fire retardant for plastics, pharmaceuticals, shrink-proofing wool.
  • Additional Notes:

Bromine Menu

  • Bromine Page One
  • Bromine Page Two
  • Bromine Page Three

References

A list of reference sources used to compile the data provided on our periodic table of elements can be found on the main periodic table page.

Related Resources

  • Anatomy of the Atom
    Answers many questions regarding the structure of atoms.
  • Molarity, Molality and Normality
    Introduces stoichiometry and explains the differences between molarity, molality and normality.
  • Molar Mass Calculations and Javascript Calculator
    Molar mass calculations are explained and there is a JavaScript calculator to aid calculations.
  • Chemical Database
    This database focuses on the most common chemical compounds used in the home and industry.

Mass Number Of Bromine 81

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Bromine 80

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Bromine Atomic Mass

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