Can the following groups of elements be classified as Dobereiner' s triad ?
Na, Si, Cl

Explanation

To determine if the elements Na (Sodium), Si (Silicon), and Cl (Chlorine) can be classified as Dobereiner's triad, we need to follow these steps:

### Step 1: Understand Dobereiner's Triad
Dobereiner's triad is a classification of elements where three elements can be grouped together such that the atomic mass of the middle element is approximately equal to the average of the atomic masses of the other two elements.

### Step 2: Find the Atomic Masses
We need to look up the atomic masses of the elements:
- Sodium (Na) = 23 g/mol
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