Metals and non-metals in the periodic table
4 marks · NormalThe table shows whether certain oxides are basic, acidic, or amphoteric.
| Element | Oxide formula | Type of oxide |
|---|---|---|
| Sodium | \ce{Na2O} | |
| Silicon | \ce{SiO2} | |
| Aluminium | \ce{Al2O3} | |
| Sulfur | \ce{SO2} |
a) Complete the table by identifying the type of oxide for each element. [2]
b) Explain how the type of oxide can help you classify each element as a metal or non-metal. [2]
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Sodium: basic; Silicon: acidic; Aluminium: amphoteric; Sulfur: acidic
(b) Metals form basic or amphoteric oxides; non-metals form acidic oxides. If the oxide is basic or amphoteric, it's likely a metal; if acidic, it's a non-metal.
Common mistakes: Confusing acidic and amphoteric oxides; Matching formula instead of type of oxide
Show mark scheme and worked solution
Marking points
B1 · 2 marks · Correctly completes the table: Na2O: basic; SiO2: acidic; Al2O3: amphoteric; SO2: acidic
B1 · 2 marks · States or explains that metals form basic (or amphoteric) oxides, non-metals form acidic oxides; uses this pattern to classify the four elements
Worked solution
| Element | Oxide formula | Type of oxide |
|---|---|---|
| Sodium | \ce{Na2O} | basic |
| Silicon | \ce{SiO2} | acidic |
| Aluminium | \ce{Al2O3} | amphoteric |
| Sulfur | \ce{SO2} | acidic |
Metals form basic or amphoteric oxides (sodium, aluminium); non-metals form acidic oxides (silicon, sulfur). The type of oxide reveals metallic/non-metallic character.