Question: 17 cl 35.453 what is the atomic number of this element
[{'answer': '17', 'provenance': [{'wikipedia_id': '5667', 'title': 'Chlorine', 'start_paragraph_id': 1, 'start_character': 68, 'end_paragraph_id': 1, 'end_character': 70, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]