Answer: The number of sub-levels the for the energy level n = 4 are 4.
Step-by-step explanation:
The number of sub-levels in an energy level is determined from the azimuthal quantum number.
Principle Quantum Number: This quantum number describes the size of the orbital. It is represented by n where n = 1,2,3,4....
Azimuthal Quantum Number: This quantum number describes the shape of the orbital and also determines the sub-levels in an energy level. It is represented by the symbol 'l'. The value of 'l' ranges from 0 to (n-1). For l = 0,1,2,3... the orbitals are s, p, d, f...
For n = 4, the value of l = 0(s), 1(p), 2(d), 3(f) and these are the number of sub-levels.
Hence, the number of sublevels the for the energy level n = 4 are 4.