Answer:
NaBr
Explanation:
Both compounds are electrovalent compounds, that is they are held together by electrovalent combination. Potassium bromide (KBr) has a melting point of 734 °C while sodium bromide (NaBr) has a melting point of 747 °C. The reason for this is because the electropositivity of potassium is higher than that of sodium.
Electrovalent combination involves the transfer the electrons from one constituent atom (to form a cation) to another constituent atom (to form an anion). Electropositivity is the tendency of an atom to donate electron(s) to form a cation. Since, it's easier for potassium (when compared to sodium) to donate its outermost electron to bromine, NaBr will have a higher force of attraction than KBr and hence a higher melting point.
