Metals are the “glittering” members of the periodic table. They are good conductors of heat and electricity, feel warm to the touch, and are usually shiny. When a metal atom gives up one or more electrons, it becomes a positively charged ion (\$M^+\$). This ion can then combine with other species, such as acids, water or oxygen, to form new compounds.
Think of a metal atom as a person who likes to share its “energy” (electrons). When it shares, it becomes a “positive friend” (\$M^+\$) that can bond with other atoms or ions.
Metals give up electrons to hydrogen ions in acids, producing hydrogen gas and a metal salt.
| Metal (M) | Acid (H⁺) | Products |
|---|---|---|
| Na | HCl | NaCl + H₂↑ |
| Zn | H₂SO₄ (dilute) | ZnSO₄ + H₂↑ |
⚡️ Key point: The reaction is faster for metals that are higher on the reactivity series (e.g., Na, K, Mg).
Remember the general equation: \$M + 2H^+ \rightarrow M^{2+} + H_2\$. Write the balanced equation and identify the metal salt formed.
Not all metals react with cold water, but many react with steam (hot water vapor) to give oxides or hydroxides and hydrogen gas.
🔥 Analogy: Think of steam as a “hot friend” that can help the metal “shake hands” with oxygen, forming a new compound.
When asked to write the reaction of a metal with steam, include the product oxide/hydroxide and note the temperature condition.
Metals combine with oxygen to form metal oxides. The reaction is often exothermic and produces heat and light.
| Metal (M) | Oxide Formed | Reaction Example |
|---|---|---|
| Fe | Fe₂O₃ (rust) | 4Fe + 3O₂ → 2Fe₂O₃ |
| Cu | CuO | 2Cu + O₂ → 2CuO |
🌬️ Analogy: Oxygen is like a “sticky” friend that bonds with metals, forming a new “coat” (oxide) that protects or changes the metal’s appearance.
When writing the oxidation reaction, balance the equation and note whether the metal is a “strong” or “weak” oxidising agent based on its position in the reactivity series.
💡 Remember: The reactivity series helps predict how quickly a metal will react in each situation. Practice balancing equations and identifying products to ace the exam!