Which quantum number determines the (a) shape (b) orientation and (c) size of the orbital ?

Explanation

To determine the quantum numbers that define the shape, orientation, and size of an orbital, we can break it down step by step:

### Step-by-Step Solution:

1. **Understanding Quantum Numbers**: Quantum numbers are a set of numbers that describe the position and energy of an electron in an atom. They provide information about the electron's energy level, shape, orientation, and size of the orbital.

2. **Shape of the Orbital**:
- The quantum number that determines the shape of the orbital is the **azimuthal quantum number (l)**.
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