Question

which answer completes the chart? 26 fe iron 6.941 chemical symbol element name atomic mass atomic number electron level formula code reactivity factor

Explanation:

In the periodic - table, each element has a unique atomic number. The number 26 in the box represents the atomic number of iron (Fe). Electron levels describe the distribution of electrons in an atom, formula code is not a standard term for elements in this context, and reactivity factor is related to how an element reacts with others. The missing label for the number 26 is atomic number.

Answer:

atomic number