What are the principal energy level? And what do they represent?

the principal energy level of an electron refers to the shell or orbital in which the electron is located relative to the atoms nucleus. the first element in a period of the periodic table introduces a new principal energy level.

Explanation:

the electrons surrounding an atom are located in region around the nucleus called "energy level".

a plasma is a warm ionized gasoline consisting of approximately equal numbers of definitely charged ions and negatively charged electrons. the characteristics of plasmas are notably unique from the ones of ordinary neutral gases in order that plasmas are considered a awesome "fourth kingdom of remember."

- lead + phosphoric acid = hydrogen + lead(ii) phosphate