Answer:
- La juventud
- El tema
- La educación
- La cabeza
- La artista (fem.)
- La inmortalidad
- La mano
- El día
- La cumbre
- El Misisipí (river)
- La sobrina
- El tren
- El artistia (masc.)
- La flor
- El martes
- La be (letter)
- La libertad
- La gente
- El mapa
- El cura (priest)
- La cura (cure)
Step-by-step explanation:
This are nouns that have, like all words in Spanish, a gender associated to them.
You asked, for example, for artista both for the masculine and the feminine way, in this case you use el or la to distinguish between one or the other.
Another interesting example would be cura with different gender. In this case cura as masculine refers to a priest but the same word, cura, with it's femenine version, means the cure.