Answer:
The atom is oxidized is Ca.
Step-by-step explanation:
- The oxidation-reduction reaction contains a reductant and an oxidant (oxidizing agent).
- The oxidation process is the process in which electrons are lost and produce positively charged ions.
- The reduction process is the process in which electrons is gained and negatively charge ions are produced.
- In the reaction of chlorine with calcium:
Ca + Cl₂ → CaCl₂,
Ca loses 2 electrons and is oxidized to Ca²⁺. (Ca → Ca²⁺ + 2e).
Cl is gains 2 electrons in "Cl₂, oxidation state zero" and is reduced to Cl⁻. (Cl₂ + 2e → 2Cl⁻).