Does every magnet have a north and south pole?

yes
no

How are series and parallel circuits simililar? both have multiple paths for electrons to travel. both require resistors in their circuits. both require a switch to complete the circuit. both have at least one path for electrons to travel.

What is the coefficient of kinetic friction μk between the block and the tabletop?

How many neutrons does element x if it’s atomic number is 28 and its mass number is 87