Science (086) — AI-generated practice question

Metal oxides vs. Non-metal oxides in water:
Metals combine with oxygen to form basic oxides, which dissolve in water to give bases (alkalis).
Example: $\text{CaO} + \text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2$ (calcium hydroxide — a base)

Non-metals form acidic oxides, which dissolve in water to give acids.
Example: $\text{SO}_3 + \text{H}_2\text{O} \rightarrow \text{H}_2\text{SO}_4$ (sulphuric acid)

Give-and-take process (ionic bonding):
Metals have 1–3 electrons in their outermost shell, which they tend to lose, forming positive ions. Non-metals have 5–7 electrons and tend to gain electrons to complete their octet, forming negative ions.
For example, sodium (2,8,1) loses one electron to chlorine (2,8,7), forming Na⁺ and Cl⁻. The oppositely charged ions attract each other, producing an ionic (electrovalent) compound — sodium chloride (NaCl).

Source: Chapter 3 — Metals and Non-metals, Section 3.3

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• Examiners expect you to name the type of oxide (basic/acidic), give a chemical equation as the example, and name the product.
• For the give-and-take part: mention electron loss (metal → cation) and electron gain (non-metal → anion) with a specific example (Na + Cl is standard from the textbook), and name the resulting compound type as ionic/electrovalent.
• Do not forget to write the resulting compound name — that is usually the last mark point.