Question: who stated the law of conservation of mass
[{'answer': 'Antoine Lavoisier', 'provenance': [{'wikipedia_id': '145040', 'title': 'Conservation of mass', 'start_paragraph_id': 3, 'start_character': 245, 'end_paragraph_id': 3, 'end_character': 262, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '145040', 'title': 'Conservation of mass', 'start_paragraph_id': 20, 'start_character': 0, 'end_paragraph_id': 20, 'end_character': 882, 'bleu_score': 0.985662154730604, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2674666105199370858}, 'section': 'Section::::History.:Discoveries in chemistry.\n'}]}]