Question

The number of orbitals in a quantum shell is equal to :

• A. 2n${}^2$
• B. (2n + 1)
• C. n
• D. n${}^2$

Answer 1

The correct option is D n${}^2$

The principal quantum number, n (the energy level)

• determines the size of an orbital (larger n = bigger orbitals)

• largely determines the energy of the orbital (larger n = higher energy)

• can take on integer values n = 1, 2, 3, ...,

• all electrons in an atom with the same value of n are said to belong to the same principle energy level

The azimuthal quantum number, l (the sublevel)

• designates the overall shape of the orbital within a shell

• affects orbital energies (larger = higher energy)

• all electrons in an atom with the same value of are said to belong to the same sublevels

• only integer values between 0 and n-1 are allowed

• sometimes called the orbital angular momentum quantum number

• spectroscopists use the following notation for sublevels