A metal M forms an oxide having the formula `M_(2)O_(3)`. It belongs to 3rd period in the modern periodic table. Write the atomic number and valency of the metal.

Explanation

To solve the question, we need to determine the atomic number and valency of the metal M that forms the oxide M₂O₃ and belongs to the 3rd period of the modern periodic table. Here’s a step-by-step solution:

### Step 1: Analyze the formula of the oxide
The given oxide is M₂O₃. This indicates that there are 2 atoms of metal M for every 3 atoms of oxygen.

### Step 2: Determine the charge of oxygen
Oxygen is a non-metal and typically has a valency of -2. Since there are 3 oxygen atoms in the formula, the total negative charge contributed by oxygen is:
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