Which metal(s) can be oxidized with a sn2+ solution but not with an fe2+ solution? (hint: the reactions are occurring under standard

For this we have to consider the reactive series of metals in which metals are arranged according to their reactivity order.

Oxidation of a metal can be defined as ability to lose electrons to become positively charged metal and a metal will lose its electrons by reacting with a metal that is having low chemical reactivity as a higher reactive metal can lose its electrons to a low reactive metal. So here a metal should be one that is more reactive than tin so that it can lose its electrons to tin to become positively charged and less reactive than iron so that it will not give its electrons to iron to become positively charged. If we look into reactive series of metal than we will find that nickel is the example of a metal that is more reactive than tin and less reactive than iron.

what is the general relationship between a galaxy's distance from earth and its speed?

the answer is:

the farther away a galaxy is from us, the faster it is moving away from us.

the answer to this question is 3.