Successes is the plural form of the noun success.
Children or kids
No, Atlantis is a singular noun (a proper noun). It is the name of a place; the word place is singular.
The word "sew" is a verb, not a noun. There is no plural for sew.
The plural form of the singular noun notch is notches.
The irregular plural form for the noun knife is knives.
Buffalos
Shelves
Mitochondria
The noun success becomes the adjective successful.
Yes, the noun 'success' is a common noun; a general word for the accomplishment of an aim or purpose; a word for any success of any kind.
No, it is not a preposition. Success is a noun.
Yes it's a noun and also economic success is actually the answer to prosperity and prosperity is economic success