What valency will be shown by an element having atomic number 12?

Explanation

To determine the valency of an element with atomic number 12, follow these steps:

### Step 1: Identify the Element
The atomic number 12 corresponds to the element magnesium (Mg).

### Step 2: Determine the Electronic Configuration
To find the electronic configuration of magnesium, we need to distribute the electrons in the shells:
- The first shell (K shell) can hold a maximum of 2 electrons.
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