How many valence electrons are present in sodium with atomic number 11 ?
Hint `: 1s^(2) 2s^(2) 2p^(6) 3s^(1) `

Explanation

To determine the number of valence electrons in sodium (Na) with an atomic number of 11, we can follow these steps:

### Step 1: Identify the Atomic Number
The atomic number of sodium is 11, which means it has 11 electrons.

### Step 2: Write the Electronic Configuration
The electronic configuration of sodium can be written as:
\[ 1s^2 \, 2s^2 \, 2p^6 \, 3s^1 \]
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