Which of the following metals directly combine with hydrogen gas to give a hydride? — Hydrogen Chemistry Question

💡 Solution & Explanation

I need to identify which metal directly combines with hydrogen gas to form a hydride. However, I notice the options aren't provided in your question. Let me explain the **general principle** so you can identify option C: ## Metals that Directly Combine with $H_2$ to Form Hydrides: **Reactive metals** (especially those with incomplete d-orbitals or high electronegativity) can directly combine with hydrogen: 1. **Alkali metals** ($Na, K, Li$): Form ionic hydrides like $NaH, KH$ 2. **Alkaline earth metals** ($Ca, Ba, Mg$): Form ionic hydrides like $CaH_2, BaH_2$ 3. **d-block metals** ($Ni, Pd, Pt$): Form interstitial hydrides (e.g., $PdH$) 4. **Transition metals** with variable oxidation states can form hydrides ## Metals that DON'T Directly Combine with $H_2$: - **Noble metals** ($Au, Ag, Cu$): Too unreactive - **Less reactive metals** ($Pb, Sn$): Require special conditions or don't form stable hydrides ## Answer Logic: Option **C** is likely a reactive metal (alkali, alkaline earth, or transition metal) that satisfies: $$\text{Metal} + H_2 \rightarrow \text{Metal Hydride}$$ **Without seeing the options**, if C is something like $Na, Ca, Ni,$ or $Pd$, it would be correct because these directly form hydrides. Options A, B, and D likely contain unreactive or noble metals that don't readily combine with $H_2$. *Please share the options for a more specific answer!*