All the energy levels are called excited state when the value of the principal quantum number is

Options

A. `n = 1`
B. `n gt 1`
C. `n lt 1`
D. `n gt - 1`

Explanation

To determine when all energy levels are considered excited states based on the principal quantum number, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Principal Quantum Number (n)**: The principal quantum number, denoted as \( n \), indicates the main energy level of an electron in an atom. It can take positive integer values: \( n = 1, 2, 3, \ldots \).

2. **Identify Ground State**: The ground state of an atom is when the electrons are in the lowest possible energy levels. This occurs when \( n = 1 \). Therefore, the first energy level (or shell) is the ground state.

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