Question

which element has similar chemical properties as sodium but has 7 energy levels? rubidium (rb) cesium (cs) potassium (k) francium (fr)

Explanation:

Elements in the same group of the periodic - table have similar chemical properties. Sodium (Na) is in Group 1. Rubidium (Rb), Cesium (Cs), Potassium (K), and Francium (Fr) are also in Group 1. The number of energy levels is related to the period number. Francium is in the 7th period, so it has 7 energy levels.

Answer:

Francium (Fr)