What type of reaction is most likely to occur when barium reacts with fluorine? write the chemical equation for the reaction?

Answer is: this is synthesis reaction.

Chemical reaction: Ba + F₂ → BaF₂.

Synthesis reaction is a type of reaction in which multiple reactants combine to form a single product.

In barium fluoride, barium has oxidation number + 2 and fluorine has oxidation number - 1, so compound has neutral charge.