Answer:
The correct option is A. KBr
Explanation:
A ionic bond take place between two ions with different charges (cations and anions). In this case K+ (cation) and Br- (anion). The semireactions that gives rise to cation and anion and then to the KBr molecule are:
K⇒ (K+) + 1e- K oxidizes and release an electron.
Br + 1e- ⇒ Br- Br reduces acepting the electron released.
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K + Br + 1e- ⇒ K+Br- + 1 e-