Answer: There are three main places where volcanoes originate: Hot spots, Divergent plate boundaries (such as rifts and mid-ocean ridges), and. Convergent plate boundaries (subduction zones)
Explanation:
Volcanoes often form in the areas where tectonic plates make contact. The friction created between two plates by the constant movement melts the Earth's crust, causing the rock underneath the crust to turn into magma due to the great temperatures created by friction. ... Volcanoes may be formed at subduction zones
Answer: 
Explanation:
Here Mn undergoes oxidation by loss of electrons, thus act as anode. silver undergoes reduction by gain of electrons and thus act as cathode.
Where both 
are standard reduction potentials.
![E^0_{[Mn^{2+}/Mn]}= -1.18V](https://tex.z-dn.net/?f=E%5E0_%7B%5BMn%5E%7B2%2B%7D%2FMn%5D%7D%3D%20-1.18V)
![E^0_{[Ag^{2+}/Ag]}=+0.80V](https://tex.z-dn.net/?f=E%5E0_%7B%5BAg%5E%7B2%2B%7D%2FAg%5D%7D%3D%2B0.80V)
![E^0=E^0_{[Ag^{+}/Ag]}- E^0_{[Mn^{2+}/Mn]}](https://tex.z-dn.net/?f=E%5E0%3DE%5E0_%7B%5BAg%5E%7B%2B%7D%2FAg%5D%7D-%20E%5E0_%7B%5BMn%5E%7B2%2B%7D%2FMn%5D%7D)
The standard emf of a cell is related to Gibbs free energy by following relation:
= gibbs free energy
n= no of electrons gained or lost = 2
F= faraday's constant
= standard emf = 1.98V
Thus the value of is
I think the anwser is A but I'm not sure so I might need to get somebody else's opinion like i said I'm sorry if it's wrong
