An academic essay is a paper in which the author tries to persuade the reader about something by providing evidence; also, academic essays should address the reader in a formal tone and voice, this means the author avoids using contractions, colloquial words such as slangs, phrasal verbs and first-person pronouns, also formal tone and voice in essays imply using third person pronouns, connecting ideas by formal linking verbs and choosing the appropriate vocabulary that means avoiding informal words or words that express a judgement from the author of the essay and instead choosing a more formal word with the same meaning, in this way the author can express his voice (personal features of writing), but communicate ideas in a formal way. Considering this "Ralph was a rational boy" show a formal tone and voice because it describes Ralph but avoid providing a personal judgment such as good or gnarly, also, the word "rational" is more formal than intelligent or similar more informal words.
4. Alymer was obssessed with Georgianna's birthmark but not because its beautiful but because he's a scientist and he's obssessed with the possibility of it's removal.