Electrophilic reagents are chemical species which, in the course of chemical reactions, acquire electrons, or a share in electrons, from other molecules or ions. Although this definition embraces all oxidizing agents and all Lewis acids, electrophilic reagents are ordinarily thought of as cationic species, such as H⁺, NO₂⁺, Br⁺, or SO₃ (or carriers of these species such as HCl, CH₃ COONO₂, or Br₂), which can form stable covalent bonds with carbon atoms. Electrophilic reagents frequently are positively charged ions (cations).