Answer to Question #236912 in General Chemistry for stoi

Question

A ceramic plate has a shiny rim. The ceramic plate is mostly composed of silicon and oxygen atoms. The shiny rim is mostly silver. When the plate is heated in a microwave oven, sparks are observed. Compare the ionization energy values of silver to those of the silicon and oxygen atoms. Explain what is happening in the oven. Why are microwaveable containers usually non-metallic? Why are most pots and pans metallic?

Answer 1

The ionization energy of silver is IE = 7.5762 eV

The ionization energy of carbon is IE =11,2603 eV

The ionization energy of silicon is IE =8.1517 eV

Silver being a metal naturally shows a low ionization energy due to the size as well as configuration. [Kr] 4d¹⁰ 5s¹

The last e in 5s is readily lost making silver one of the best conductors of heat and electricity too. That is why most pots and pans metallic. They convey heat uniformly and easily.

Carbon has the highest ionization energy among all due to its non metallic nature and the uptight configuration, not allowing it lose the e^- in outer shell. 

Down the group, IE decreases and hence lower energy is for silicon.

Inside the oven, when the microwaves interact with the metal, the outer e^-, they sometimes gain energy enough to move out of the surface and lead to a spark generation. That is why microwaveable containers are usually non-metallic.

Non metals have a very high ionization energy, which makes it difficult for low energy microwaves to knock them out of surface.