Consider a voltaic cell based on the following cell reaction:
ni(s) + at2(s) ? ni2+(aq) + 2at– (aq)
given that the standard cell emf is 0.55 v, what is the standard reduction potential for astatine? [e°(ni2+/ni) = –0.25 v]

Explanation:

Here Ni undergoes oxidation by loss of electrons, thus act as anode. At undergoes reduction by gain of electrons and thus act as cathode.

Where both are standard reduction potentials.

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.