Final answer:
The electron configuration representing an element that reacts in a similar way to sodium is 1s²2s²2p¶3s²3p¶4s¹, corresponding to the alkali metal potassium, which has a single valence electron.
Step-by-step explanation:
The element that reacts similarly to sodium, which has a noble gas configuration of [Ne] 3s¹ and reacts vigorously with water, would need to have one valence electron as well. The electron configuration representing an element that reacts in a similar way is 1s²2s²2p¶3s²3p¶4s¹ (D). This configuration corresponds to the alkali metal potassium (K), which, like sodium, also has a single valence electron in its outermost shell that leads to similar chemical reactivity, including a vigorous reaction with water.