What would you observe in the reaction of calcium with nitric acid​

reacts to form carbondioxide

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).