= Salt bridge
{wiki}
A <salt bridge> is an ionic connection between <electrolyte> compartments that limits bulk mixing while permitting <electric charge> transport. Its mobile <ions> compensate changes caused by the <electrode> <half-reactions>, keeping the bulk <chemical solutions> approximately electrically neutral during sustained <electric current>. It does not conduct <Electrons> like the external wire, and its <ions> need not be consumed at either <electrode>. The ionic return path and compensating ion flows are explained in https://chemed.chem.purdue.edu/genchem/topicreview/bp/ch20/electro.php[Purdue University, Electrochemical Reactions: salt bridge and charge balance].
In a discharging <Daniell cell>, <anions> moving toward the <anode> compartment and <cations> moving toward the <cathode> compartment both contribute to the internal <conventional current> from <anode> toward <cathode>. This charge-balance role is compatible with a negative <anode>: terminal signs do not imply that the whole <anode> <chemical solution> is negatively charged. The simple compensating-inventory example in <Daniell cell> does not fix all individual <ion> fluxes; <diffusion> and the cell's other mobile <ions> can contribute. A real bridge also introduces <electrical resistance> and may introduce a junction <electric potential difference>, so its presence does not guarantee an exact thermodynamic cell reading. See https://goldbook.iupac.org/terms/view/09080[IUPAC Gold Book: salt bridge and liquid-junction potential].
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