Na$_2$X  ⇌  2Na$^+$  +  X$^{2-}$ The bond between Na and X is likely to be

1. Analyze the question

The question presents a dissociation equation: Na$_2$X ⇌ 2Na$^+$ + X$^{2-}$. You are asked to identify the type of chemical bond existing between Sodium (Na) and the element X based on the ions formed.

2. Explain the concept

• Ionic Bonding: This occurs when there is a complete transfer of electrons from a metal to a non-metal, resulting in the formation of oppositely charged ions (cations and anions). These ions are held together by strong electrostatic forces of attraction.
• Key Indicators: • Sodium (Na) is a Group 1 metal (highly electropositive). • The dissociation shows the formation of a positive ion (Na$^+$) and a negative ion (X$^{2-}$). • Whenever a compound dissociates into ions in a solvent (like water), it is a strong indicator that the bond holding the atoms together in the solid state was ionic.

3. Show the solution

• Step 1: Look at the components. Sodium (Na) is a metal, and X is a non-metal (since it forms a negative ion, X$^{2-}$).
• Step 2: Observe the reaction. The equation shows the compound splitting into its constituent ions. This process is called electrolytic dissociation.
• Step 3: Apply the definition. Compounds that dissociate into ions in this manner are typically ionic compounds. The bond between a metal (Na) and a non-metal (X) that results in the formation of ions is an ionic bond (also known as an electrovalent bond).

4. Identify the answer

The bond between Na and X is ionic because it involves the transfer of electrons from the metal to the non-metal, creating ions that are held by electrostatic attraction.

5. Exam Tip

Memory Trick: Remember the "M-N" rule: If you see a Metal bonded to a Non-metal, it is almost always an Ionic bond. If you see two Non-metals bonded together, it is usually a Covalent bond.