(a) Show the formation of `Na_2O` and MgO by the transfer of electrons.
(b) What are the ions present in these compounds?

Explanation

### Step-by-Step Solution

**(a) Formation of Na₂O and MgO by the transfer of electrons:**

1. **Formation of Na₂O:**
- Sodium (Na) has an atomic number of 11, which gives it an electronic configuration of 2, 8, 1. This means sodium has 1 valence electron.
- Oxygen (O) has an atomic number of 8, with an electronic configuration of 2, 6. This means oxygen has 6 valence electrons and needs 2 more electrons to complete its octet.
- To form Na₂O, two sodium atoms will each lose 1 electron.
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