Selenium vs Bromine

Side-by-side comparison of Selenium (Se, element 34) and Bromine (Br, element 35) by atomic structure and physical properties.

← Back to Periodic Table
PropertySe Selenium Br Bromine
Atomic number3435
SymbolSeBr
NameSeleniumBromine
Categorynonmetalhalogen
Standard Atomic Weight78.971 u79.904 u
Period44
Group1617
Blockpp
Phase at STPSolidLiquid
Electron configuration[Ar]3d104s24p4[Ar]3d104s24p5
Oxidation states[-2, -1, 0, 1, 2, 3, 4, 5, 6][-1, 1, 2, 3, 4, 5, 7]
Electronegativity (Pauling)2.552.96
Electron affinity2.0206 eV3.3635 eV
Density4809 kg/m³3102.8 kg/m³
Melting point220.5 °C-7.2 °C
Boiling point684.85 °C58.8 °C
Discovery year18171825

Key Differences

PropertySe SeleniumBr Bromine
Standard Atomic Weight78.971 u ↓ lower79.904 u ↑ higher
Density4809 kg/m³ ↑ higher3102.8 kg/m³ ↓ lower
Melting point220.5 °C ↑ higher-7.2 °C ↓ lower
Boiling point684.85 °C ↑ higher58.8 °C ↓ lower
Electronegativity (Pauling)2.55 ↓ lower2.96 ↑ higher
Electron affinity2.0206 eV ↓ lower3.3635 eV ↑ higher
Group16 17
Categorynonmetal halogen
Phase at STPSolid Liquid
Electron configuration[Ar]3d104s24p4 [Ar]3d104s24p5
Discovery year1817 1825