Given an trivia question precisely answer the question with a word/phrase/name. External resources such as Wikipedia could be used to obtain the facts.

Of the five Marx brothers who appeared on film, who was the oldest ?
chico

Which of the wives of Henry VIII was born in Madrid in 1485?
catherine of aragon

From the Latin for Kalium, what element, with an atomic number of 19, uses the symbol K?
potassium