The ancient Greek Gods did not have second (or family) names.
Mars Candybars
no!
Greek gods, and goddesses drank wine.
It's impossible for a mortal to become a God
Roman gods and goddesses are pretty much the same, they just have different names.
Greek gods/goddesses did not have "last names" they had titles/epithets.
Greek mythology came first. Then the Romans came. They admired the gods and goddesses of the Greeks and copied. The Roman gods and goddesses and more disciplined and war-like. Because Greek and Roman mythology things can't have the same name, Romans changed the names.
There are twelve main gods and goddesses(the Olympians), but there are lots of other minor gods and goddesses in Greek mythology.
no they had special powers
There were no Greek gods that had names starting with 'v'; however, there were several Roman goddesses such as 'Venus' and 'Vesta'.
Yes, there were literally hundreds of gods that the Romans had adopted into their culture from their conquests of other empires.