Answer:
a) Lead
b) Below
Step-by-step explanation:
a) ₂₁₀ Po⁸⁴ ⇒ α + ₂₀₈Pb⁸²
b) Acids are extremely corrosive substances, so they must be cleaned soon as possible because they can damage not only the furniture but also clothes and skin of the laboratory workers.
Before cleaning the polluted area with water, acids must be clean with towels in order to reduce the amount of acid.
The reaction between the acids and water are very explosive, they are exothermic reactions, that means that they increase the temperature of the area polluted and it can cause more damage. That's why the area must be cleaned with towel before add water.