Jim brings his finger near a metal doorknob and receives a shock what does this demonstrates

Static Electricity

Explanation:

Most likely, in the room, Jim was building up static electricity by friction with the floor, which he released upon contact with a metal object.

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.