Which lists the elements in order from most conductive to least conductive? potassium (k), selenium (se), germanium (ge) germanium (ge), potassium (k), selenium (se) selenium (se), germanium (ge), potassium (k) potassium (k), germanium (ge), selenium (se)

The right option of this question is (D) as

Potassium → Germanium → Selenium

In the period, as the trend increase from left to right, the property of electrical conductivity of the elements decreases. There is the number of factors that affect this property such as moving from left to right in the period, the number of protons and electrons increase but the electrons remain in the same shell. Its mean the increasing number of proton exerts more force of attraction on the electrons of the outer shell. That force of attraction reduces or remove the ability of the element to conduct electricity. But increasing number of electrons in the same shell also increase the electrons repulsion. As we see in the periodic table, the Potassium exists in the metallic group but Germanium and Selenium exist almost in the nonmetallic group. So, the right option is (D).