The two elements that have the same number of energy levels with electrons in them are krypton and neon.
Both krypton (Kr) and neon (Ne) are in the same period (row) of the periodic table and have the same number of electron shells (energy levels) filled with electrons, although krypton has more total electrons due to being a heavier element. Neon has 2 electron shells, and krypton has 4 electron shells, but their filled energy levels or shells can be compared similarly based on their respective configurations. In this case, the answer based on the proper context is that similarly filled shells can be considered.
However, if we strictly refer to the number of filled shells, krypton would not be a fair match for neon due to their different periods.
For clarification, if we are looking only at the number of electron shells, lithium and francium both have a total of 3 energy levels.
Thus the best more correct answer would be lithium and francium if considered strictly from the perspective of filled energy level shells, as they share a similar number of levels though they are in different groups.
If this is a confusion, please clarify the criteria used to determine the matching pairs across periods or energy levels, so I may provide an appropriate concurrence.
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