What is the maximum number of d orbitals in a principal energy level?

The answer is: 5 d-orbitals.

Principal quantum number (n) describes the size of the orbital.

There are one s orbital (angular quantum number l=0), three p orbitals (angular quantum number l=1 and magnetic quantum number ml = -1,0,+1) and five d orbitals (angular quantum number l=2 and magnetic quantum number ml = -2,-1,0,+1,+2).

d-orbitals are butterfly shaped.

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.