CDS Chemistry · Metals and Non-Metals
Properties of Metals, Non-Metals and Metalloids
The physical properties that mark a metal, the non-metals that break the rules, and the metalloids that sit between.
Why this matters
Five CDS questions, all EASY or MODERATE. Each asks for one property by its name (sonorous, ductile) or for the exception to a rule, such as the non-metal that shines.
Concept 1 of 2: Physical properties of metals
Definition
The words to know:
- Malleable: can be beaten into sheets. Ductile: can be drawn into wires. Gold is the most malleable and ductile metal; silver is next.
- Sonorous: rings when struck, which is why bells are made of metal.
- Lustrous: shiny surface.
- Conductors: silver is the best conductor of heat and electricity, then copper. Lead and mercury are poor conductors for metals.
- Exceptions: mercury is a liquid at room temperature; sodium and potassium are soft enough to cut with a knife.
| Property | Meaning | Example |
|---|---|---|
| Malleable and ductile | Beaten into sheets; drawn into wires | Gold, the best at bothQ |
| Sonorous | Rings when struck | School bellsQ |
| Lustrous | Shiny surface | Polished silver |
| Good conductor | Carries heat and electricity | Silver best, then copperQ CDS 2022 (II): silver and copper are the pair of very good heat conductors; lead and mercury are poor. |
Practice this concept4 quick reps
The same idea in a real exam question:
Example 1 · Metals and Non-Metals · Properties of Metals, Non-Metals and Metalloids
Mercury is neither malleable nor ductile
Concept 2 of 2: Non-metals that break the rules, and metalloids
Definition
The exceptions and the in-between:
- Iodine is a non-metal with a metallic lustre.
- Graphite (carbon) conducts electricity; diamond (carbon) is the hardest natural substance.
- Metalloids show properties of both metals and non-metals: boron, silicon, germanium, arsenic, antimony, tellurium. Silicon and germanium are semiconductors.
- Coke is a form of carbon and sugar a compound of carbon; neither is a metalloid.
| Element | Kind | Notable property |
|---|---|---|
| Iodine | Non-metal | Lustrous (shiny)Q CDS 2021 (I): iodine is the non-metal that is lustrous. Silicon and germanium are metalloids, not non-metals. |
| Graphite | Non-metal (carbon) | Conducts electricity |
| Diamond | Non-metal (carbon) | Hardest natural substance |
| Germanium | Metalloid | SemiconductorQ |
| Silicon | Metalloid | Semiconductor |
| Boron, arsenic, antimony, tellurium | Metalloids | Properties of both metals and non-metals |
Practice this concept4 quick reps
The same idea in a real exam question:
Example 2 · Metals and Non-Metals · Properties of Metals, Non-Metals and Metalloids
Silicon and germanium are metalloids
Summary — formulas & gotchas at a glance
A revision cheat-sheet for the formulas and gotchas above. Click any concept name to jump back to its full explanation.
Reference tables (2)
Physical properties of metals4 rows
| Property | Meaning | Example |
|---|---|---|
| Malleable and ductile | Beaten into sheets; drawn into wires | Gold, the best at bothQ |
| Sonorous | Rings when struck | School bellsQ |
| Lustrous | Shiny surface | Polished silver |
| Good conductor | Carries heat and electricity | Silver best, then copperQ CDS 2022 (II): silver and copper are the pair of very good heat conductors; lead and mercury are poor. |
Non-metals that break the rules, and metalloids6 rows
| Element | Kind | Notable property |
|---|---|---|
| Iodine | Non-metal | Lustrous (shiny)Q CDS 2021 (I): iodine is the non-metal that is lustrous. Silicon and germanium are metalloids, not non-metals. |
| Graphite | Non-metal (carbon) | Conducts electricity |
| Diamond | Non-metal (carbon) | Hardest natural substance |
| Germanium | Metalloid | SemiconductorQ |
| Silicon | Metalloid | Semiconductor |
| Boron, arsenic, antimony, tellurium | Metalloids | Properties of both metals and non-metals |
Watch out for (2)
- Mercury is neither malleable nor ductile→ Physical properties of metals
- Silicon and germanium are metalloids→ Non-metals that break the rules, and metalloids
Test yourself on Metals and Non-Metals
10 past CDS questions from this chapter, timed at 10 minutes and marked the way the exam marks it. You see your score and every answer the moment you finish. Free to start.