Question: where is the majority of the mass of an atom found
[{'answer': 'in the nucleus', 'provenance': [{'wikipedia_id': '902', 'title': 'Atom', 'start_paragraph_id': 2, 'start_character': 291, 'end_paragraph_id': 2, 'end_character': 305, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '902', 'title': 'Atom', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 650, 'bleu_score': 0.8201285971794041, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5240553376457568897}, 'section': 'Section::::Abstract.'}]}]