Question

In the balanced redox reaction: 2 cu(s) + s(s) ? cu2s(s), how many electrons are gained or lost by each sulfur atom?

Answer 1

2Cu + S = Cu₂S

S⁰ + 2e⁻ = S⁻²
Cu⁰ - 1e⁻ = Cu⁺¹

A sulfur atom gains two electrons.