For the oxidation–reduction reaction equation 2 Rb + Br 2 ⟶ 2 RbBr 2Rb+Br2⟶2RbBr indicate how many electrons are transferred in the formation of one formula unit of product.

2e⁻ are transferred in the formation of one formula unit of product

Explanation:

The reaction is:

2Rb + Br₂ → 2RbBr

In ground state, both elements have 0 as oxidation state.

In the RbBr, Rb acts with+1 and Br with -1.

Rb increased the oxidation state → Oxidation

Br decreased the oxidation state → Reduction

Rb → Rb⁺ + 1e⁻

Br₂ + 2e⁻ → 2Br⁻

Bromine had to gained 2 electrons, to decreased the oxidation state, so

(Rb → Rb⁺ + 1e⁻ ) ₓ2 = 2Rb → 2Rb⁺ + 2e⁻

(Br₂ + 2e⁻ → 2Br⁻) ₓ1 =  Br₂ + 2e⁻ → 2Br⁻

2Rb + Br₂ + 2e⁻ → 2Br⁻ + 2Rb⁺ + 2e⁻

If we cancel the electrons, we reach the balanced reaction. In conclussion, 2 e⁻

i think that the answer is c