Sometimes. Mostly not
Robin eggs are usually found in a nest made by their mother.
Almost none. The egg might not break when falling to the ground but in the absence of incubation by the mother Robin, the egg has virtually no chance of surviving. If you find an intact egg that has fallen out of a nest in a tree, you may be able to incubate it artificially and a live chick will emerge.
The parents remove the egg shells far away from the nest so that predators aren't clued in to the nest's location.
yes
they hatched or some other bird ate them
it would die
"An egg bank contains frozen donor eggs, used for reproduction. A nest egg is typically an accumulation of money used for retirement. Therefore an egg bank is not the same as a nest egg."
No, if you put it back in its nest the mother will kick it out and it will die overnight.
Yes
How big does a robin egg get before it hatches
The American Robin will see their eggs hatch in about fourteen days, after a mating season that lasts from April until July. The European Robin, a cousin of the American Robin though not as large or brightly colored, has roughly the same incubation period. Their breeding season begins in March.
Yes, without the mother nurturing, and warmth it will die. The egg was probably discarded because it was already dead, or touch by a human or other predator. The mother goose probably got rid of it as to not attract the predators back to the nest.