Compound X and aluminium are used to join railway tracks. (a) Identify the compound X (b) Name the reaction (c) Write down its reaction.

Explanation

To solve the question step by step, we will identify the compound X, name the reaction, and write down the balanced chemical equation for the reaction.

### Step 1: Identify the Compound X
- The compound X that is used to join railway tracks along with aluminum is **Iron(III) oxide**, which has the chemical formula **Fe2O3**.

### Step 2: Name the Reaction
- The reaction between Iron(III) oxide (Fe2O3) and aluminum is known as the **thermite reaction**.

...