Bromine (Br)
Bromine is one of only two elements that are liquid at room temperature (mercury is the other).
Bromine properties
- Atomic mass
- 79.904 u
- Category
- Halogen
- Group
- 17
- Period
- 4
- Block
- p-block
- State at room temp.
- Liquid
- Electronegativity
- 2.96
- Melting point
- 265.8 K (-7.3 °C)
- Boiling point
- 332 K (58.9 °C)
- Density
- 3.103 g/cm³
- Oxidation states
- +5, +1, −1
- Atomic radius
- 183 pm
- Ionization energy
- 11.814 eV
- Electron affinity
- 3.365 eV
- Radioactive
- No, has stable isotopes
- Discovered
- 1826
Bromine electron configuration
- Electron configuration
- [Ar] 3d10 4s2 4p5
- Full electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p5
- Electron shells
- 2 · 8 · 18 · 7
The electron configuration of Bromine (Br) is [Ar] 3d10 4s2 4p5. Its 35 electrons are arranged in shells as 2, 8, 18, 7.
Protons, neutrons and electrons in Bromine
A neutral Bromine atom has 35 protons and 35 electrons. Most Bromine atoms have about 45 neutrons: the atomic mass rounded to 80, minus the atomic number 35.
Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass
How many valence electrons does Bromine have?
7
Bromine has 7 valence electrons in its outermost shell, shell 4. These are the electrons involved in chemical bonding.
Bromine orbital diagram
Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations
Molar mass of Bromine
79.904 g/mol
One mole of Bromine atoms (6.022 × 10²³ atoms) has a mass of 79.904 grams. Use this value to convert between grams and moles.
Compounds containing Bromine
Bromine facts
- Bromine is one of only two elements that are liquid at room temperature (mercury is the other).
- Its name comes from a Greek word meaning 'stench' — it has a sharp, unpleasant smell.
- Bromine (Br) has atomic number 35 and is a liquid at room temperature. It was discovered in 1826.
Position in the periodic table
Bromine is element 35, in period 4 and group 17 of the periodic table, in the p-block.
Uses of Bromine
Bromine compounds are used as flame retardants in electronics, furniture foam and building insulation, although some have been restricted over health concerns. Dense bromide brines help control pressure in oil and gas wells, and bromine-based disinfectants are popular for hot tubs and swimming pools. Bromine is also used to make medicines, dyes and the silver bromide once used in photographic film.
Who discovered Bromine?
French chemist Antoine-Jérôme Balard discovered bromine in 1826 while studying seaweed ash and brine from the salt marshes of Montpellier. In Germany, Carl Löwig had isolated it independently slightly earlier but published his results later.
Where does the name come from?
Bromine comes from the Greek bromos, meaning 'stench'. Antoine-Jérôme Balard discovered the element in 1826, and the name was chosen for the sharp, unpleasant smell of its reddish-brown vapor.
Same group
Compare Bromine
FAQ
What is the electron configuration of Bromine?
The electron configuration of Bromine (Br) is [Ar] 3d10 4s2 4p5. Its 35 electrons are arranged in shells as 2, 8, 18, 7.
How many protons, neutrons and electrons does Bromine have?
A neutral Bromine atom has 35 protons and 35 electrons. Most Bromine atoms have about 45 neutrons: the atomic mass rounded to 80, minus the atomic number 35.
How many valence electrons does Bromine have?
Bromine has 7 valence electrons in its outermost shell, shell 4. These are the electrons involved in chemical bonding.
What is the molar mass of Bromine?
The molar mass of Bromine is 79.904 g/mol. This is the same number as its atomic mass, 79.904 u.
Is Bromine a metal?
No. Bromine is a halogen, so it is a nonmetal.
Is Bromine radioactive?
Ordinary Bromine is not radioactive: it has at least one stable isotope. Like every element, it also has radioactive isotopes, most of them made in laboratories.
Where is Bromine on the periodic table?
Bromine is element 35, in period 4 and group 17 of the periodic table, in the p-block.