1.2.3Atomic Structure and the Periodic Table
Metals and Non-Metals — AQA GCSE Combined Science Trilogy 8464 - Chemistry Revision Notes & Topical Questions
5 min read 6 parts Lesson 14 of 17
Part 1 of 4Position on the Periodic Table
Metals
- Metals Most elements are metals. They are found to the left and in the centre of the table.
- This includes Group 1 (alkali metals), Group 2 and the transition metals.
Non-metals
- Non-metals Non-metals are found on the right-hand side and at the top of the table, such as carbon, oxygen, chlorine and the noble gases.
- Hydrogen is also a non-metal.
The boundary
- The boundary A stepped line separates the two types.
- Elements near the line sometimes show properties of both.
Part 2 of 4Physical properties
| Property | Metals | Non-metals |
|---|---|---|
| Conduct electricity | Good conductors | Poor conductors (graphite is an exception) |
| Conduct heat | Good conductors | Poor conductors |
| Melting and boiling points | Usually high | Usually low |
| Appearance | Shiny when polished | Dull |
| Strength and hardness | Strong, malleable and ductile | Brittle when solid |
| Density | Usually high | Usually low |
| Sound when hit | Sonorous (ring) | Dull sound |
Part 3 of 4Chemical behaviour and electrons
1Atom type
- Atom type Metal atoms have few outer electrons.
- Non-metal atoms have more, so they need only a few to fill their outer shell.
2Metals lose electrons
- Metals lose electrons Metal atoms give up their outer electrons to form positive ions (cations).
3Non-metals gain or share
- Non-metals gain or share Non-metals gain electrons to form negative ions (anions), or share them in covalent bonds.
4Compounds formed
- Compounds formed Metals reacting with non-metals form ionic compounds.
- Non-metals reacting with each other form covalent compounds.
Part 4 of 4Oxides
Metal oxides
- Metal oxides Metal oxides are generally basic. Those that dissolve in water give alkaline solutions.
Non-metal oxides
- Non-metal oxides Non-metal oxides are generally acidic. Those that dissolve in water give acidic solutions.
Example
- Example Magnesium oxide is a basic oxide; sulfur dioxide is an acidic oxide.
Key terms
| Term | Meaning |
|---|---|
| Metal | An element that conducts well and forms positive ions by losing outer electrons. |
| Non-metal | An element that is usually a poor conductor and forms negative ions or shares electrons. |
| Malleable | Able to be hammered or bent into shape without breaking. |
| Ductile | Able to be drawn out into a wire. |
| Cation | A positively charged ion. |
| Anion | A negatively charged ion. |
Avoid these mistakes
1
Saying all non-metals are gases. Many are, but carbon and sulfur are solids and bromine is a liquid.
2
Assuming every metal is hard or has a high melting point. Group 1 metals are soft with low melting points.
3
Forgetting that graphite is a non-metal that conducts electricity.
4
Writing that metals gain electrons. Metals lose electrons to form positive ions.
5
Saying metal oxides are acidic. Metal oxides are generally basic and non-metal oxides acidic.
Last updated: