What is the maxium number of electrons that may be present in the fourth principal energy level of an atom?

Ineed to try to get this right so i can get a good grade so can someone me

Using the prompt, which ideas are most influenced by the petition of right? a) common law b) bill of rights c) divine right of kings d) declaration of independence

Me i really need which of these was an accomplishment of the han dynasty? the invention of the seismograph finding a water passage to europe the invention of the ballpoint pen the invention of the abacus