Which value is documented for Iron under the source-backed "atomic number" attribute?

Answer options

• Option: 29
  "29" vs. "26" 29 is stored as the atomic-number claim; misses the target mapping. 29 uses attribute atomic_number. The task targets this mapping, so 29 remains wrong in this prompt. 29 remains a separate periodic-table entry in this comparison.
• Option: 79
  "79" vs. "26" 79 is stored as the atomic-number claim; misses the target mapping. 79 uses attribute atomic_number. The task targets this mapping, so 79 remains wrong in this prompt. 79 remains a separate periodic-table entry in this comparison.
• Correct: 26
  "26" - target 26 is stored as the atomic-number claim for iron and uses the. 26 uses attribute atomic_number. The task targets this mapping, and 26 remains correct in this prompt. 26 remains a separate periodic-table entry in this comparison.
• Option: 47
  "47" vs. "26" 47 is stored as the atomic-number claim; misses the target mapping. 47 uses attribute atomic_number. The task targets this mapping, so 47 remains wrong in this prompt. 47 remains a separate periodic-table entry in this comparison.

Solution

26

"26" is correct: 26 is stored as the atomic-number claim for iron and uses the same dimensionless unit. The prompt targets 26, so the graph keeps this mapping stable against close alternatives. Source: Wikidata. As of: 2026-02-13.

Fun fact

26 carries the additional dataset detail 26. The graph therefore uses a graph attribute.