Balance the reaction which forms ions. Choose "blank" if no coefficient other than 1 is needed. ZnBr2 what Zn + + what Br- 1 or 2 or black

Explanation:

For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.  

Here zinc is having an oxidation state of +2 called as   cation and bromide is an anion with oxidation state of -1. Thus 2 atoms of will combine with one and written in simplest whole number ratios to give neutral

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