The number of orbitals in n=3 are

Options

A. 1
B. 4
C. 9
D. 16

Answer

To find the number of orbitals when the principal quantum number \( n = 3 \), we can follow these steps:

### Step 1: Understand the Principal Quantum Number
The principal quantum number \( n \) indicates the energy level of an electron in an atom. For \( n = 3 \), we are looking at the third energy level.

### Step 2: Determine the Types of Orbitals
In any given energy level \( n \), the types of orbitals present are:
- s-orbitals
- p-orbitals
- d-orbitals

For \( n = 3 \):
- There is 1 s-orbital (3s)
- There are 3 p-orbitals (3p)
- There are 5 d-orbitals (3d)

### Step 3: Count the Total Number of Orbitals
Now, we can count the total number of orbitals:
- s: 1 orbital
- p: 3 orbitals
- d: 5 orbitals

Adding these together:
\[ \text{Total orbitals} = 1 + 3 + 5 = 9 \]

### Conclusion
Thus, the total number of orbitals when \( n = 3 \) is **9**.