Here's why:

* Metal X: This is likely a reactive metal like zinc (Zn), magnesium (Mg), or iron (Fe).

* Dilute Acid Y: The most common dilute acids used in this reaction are hydrochloric acid (HCl) or sulfuric acid (H₂SO₄).

* Reaction: When a reactive metal reacts with a dilute acid, it produces hydrogen gas (H₂) and a salt.

* For example, zinc reacting with hydrochloric acid: Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)

* Burning and Explosion: Hydrogen gas is highly flammable and burns readily with a characteristic "pop" sound when ignited.

Let me know if you'd like more details about the chemical reactions involved!