The key difference between bromine and bromide is that bromide is the reduced form of bromine.
The chemical elements in the periodic table are not stable except for the noble gases. Therefore, elements try to react with other elements to gain the noble gas electron configuration to achieve stability. Likewise, bromine also has to get an electron to achieve the electron configuration of the noble gas Krypton. All metals react with bromine, forming bromides. Bromine and bromide have different physical and chemical properties due to the change of one electron.
CONTENTS
1. Overview and Key Difference
2. What is Bromine
3. What is Bromide
4. Side by Side Comparison – Bromine vs Bromide in Tabular Form
5. Summary
What is Bromine?
Bromine is a chemical element in the periodic table which is denoted by Br. It is a halogen (17th group) in the 4th period of the periodic table. The atomic number of bromine is 35; thus, it has 35 protons and 35 electrons. Its electron configuration is [Ar] 4s2 3d10 4p5. Since the p sublevel should have 6 electrons to obtain the Krypton noble gas electron configuration, bromine has the ability to attract an electron. It has a high electronegativity, which is about 2.96, according to the Pauling scale.
The atomic weight of bromine is 79.904 amu. Under room temperature, it exists as a diatomic molecule (Br2). Also, this diatomic molecule is a Red-brown colour liquid. Bromine has a melting point of 265.8 K and a boiling point of 332.0 K.
Further Properties of Bromine
Among all the bromine isotopes, Br-79 and Br-81 are the most stable isotopes. Further, this chemical element is slightly soluble in water but well soluble in organic solvents like chloroform. Moreover, it has 7, 5, 4, 3, 1, -1 oxidation states.
The chemical reactivity of bromine lies between that of chlorine and iodine. Bromine is less reactive than chlorine but more reactive than iodine. Bromine produces the bromide ion by taking up one electron. Therefore, bromine participates in ionic compound formation easily. Actually, in nature, bromine exists as bromide salts instead of Br2.
Figure 01: Bromine
Bromine can oxidize the anions of elements located below bromine in the periodic table. However, it cannot oxidize chloride to give chlorine. Moreover, we can produce Br by treating bromide-rich brines with chlorine gas. Or else bromine gas is formed by treating HBr with sulfuric acid. Bromine is very useful in industry and chemical laboratories. Bromide compounds are important as gasoline additives, for pesticides and as a disinfectant in water purification.
What is Bromide?
Bromide is the anion that forms when bromine abstracts an electron from another electropositive element. We can represent it by the symbol Br–. It is a monovalent ion with -1 charge. Therefore, it has 36 electrons and 35 protons.
The electron configuration of bromide is [Ar] 4s2 3d10 4p6. It exists in ionic compounds such as sodium bromide, calcium bromide and HBr. It also exists naturally in water sources.
What is the Difference Between Bromine and Bromide?
Bromine is a chemical element in the periodic table which is denoted by Br while Bromide is the anion that forms when bromine abstracts an electron from another electropositive element. Moreover, the key difference between bromine and bromide is that bromide is the reduced form of bromine. Besides, bromide has 36 electrons compared to 35 electrons of bromine, but both have 35 protons. Therefore, bromide has a -1 charge whereas bromine is neutral.
Furthermore, bromine is more chemically reactive than Bromide. Also, a further difference between bromine and bromide is that the bromide has achieved the krypton electron configuration and is, therefore, more stable than the bromine atom.
Summary – Bromine vs Bromide
Bromine is a chemical element in the periodic table and is denoted by Br. Meanwhile, bromide is the anion that forms when bromine abstracts an electron from another electropositive element. Further, the key difference between bromine and bromide is that bromide is the reduced form of bromine.
Image Courtesy:
1. “Bromine 25ml (transparent)” By W. Oelen – (CC BY-SA 3.0) via Commons Wikimedia
2. “Br-” By NEUROtiker – Own work (Public Domain) via Commons Wikimedia