Question

which element has atoms with valence electrons in a higher energy level than those of calcium (ca)? (1 point) cesium (cs) bromine (br) oxygen (o) lithium (li)

Explanation:

Step1: Identify calcium's period

Calcium is in period 4. Valence - electrons of an atom in period n are in the n - energy level.

Step2: Analyze each option's period

Cesium is in period 6, bromine in period 4, oxygen in period 2, and lithium in period 2. A higher - numbered period means higher - energy valence electrons.

Answer:

Cesium (Cs)