The element with atomic number 77 is Iridium. However, the name of Iridium does not directly derive from the Greek goddess of the rainbow. The name "Iridium" is derived from the Latin word "iris," which means "rainbow." It is named so because of the various colors displayed by its compounds. The Greek goddess associated with the rainbow is Iris, but the element name "Iridium" is derived from the Latin term rather than the Greek goddess.