Metals and non-metals
There are many divisions in the periodic table, but one of the most important is between the Shiny element that is a good conductor of electricity and heat, and which forms basic oxides. and the non-metals.
The metal elements are on the left of a ‘stepped line’ that runs below boron (B), silicon (Si), arsenic (As), tellurium (Te), and astatine (At).
You can tell the difference between the metals and non-metals by looking at their properties.
| Properties of a typical metal in a solid state | Properties of a typical non-metal in a solid state |
| Good conductor of electricity | Poor conductor of electricity |
| Good conductor of heat | Poor conductor of heat |
| Generally high melting points | Generally low melting points |
| Malleable (can be hammered into shape) | Brittle (breaks when hammered) |
| Ductile (can be drawn out into wires) | Brittle (snaps when stretched) |
| Sonorous (makes a ringing sound when struck) | Not sonorous |
| Properties of a typical metal in a solid state | Good conductor of electricity |
|---|---|
| Properties of a typical non-metal in a solid state | Poor conductor of electricity |
| Properties of a typical metal in a solid state | Good conductor of heat |
|---|---|
| Properties of a typical non-metal in a solid state | Poor conductor of heat |
| Properties of a typical metal in a solid state | Generally high melting points |
|---|---|
| Properties of a typical non-metal in a solid state | Generally low melting points |
| Properties of a typical metal in a solid state | Malleable (can be hammered into shape) |
|---|---|
| Properties of a typical non-metal in a solid state | Brittle (breaks when hammered) |
| Properties of a typical metal in a solid state | Ductile (can be drawn out into wires) |
|---|---|
| Properties of a typical non-metal in a solid state | Brittle (snaps when stretched) |
| Properties of a typical metal in a solid state | Sonorous (makes a ringing sound when struck) |
|---|---|
| Properties of a typical non-metal in a solid state | Not sonorous |
At room temperature:
- all the metals are solids, except mercury – it is a liquid.
- the non-metal elements hydrogen nitrogen, oxygen, fluorine, chlorine and all the noble gases (Group 0) are gases.
- bromine, a non-metal, is a liquid.
- every other element is a solid.
Groups
Elements in the same group have the same number of electrons in their outer shell, which means they have similar chemical properties
| Group | Name | Metal / Non-metal | Reactive / Non-reactive |
| 1 | alkali metals | metal | reactive |
| 2 | alkaline earth metals | metal | reactive |
| 7 | halogens | non-metal | reactive |
| 0 | noble gases | non-metal | non-reactive |
| Group | 1 |
|---|---|
| Name | alkali metals |
| Metal / Non-metal | metal |
| Reactive / Non-reactive | reactive |
| Group | 2 |
|---|---|
| Name | alkaline earth metals |
| Metal / Non-metal | metal |
| Reactive / Non-reactive | reactive |
| Group | 7 |
|---|---|
| Name | halogens |
| Metal / Non-metal | non-metal |
| Reactive / Non-reactive | reactive |
| Group | 0 |
|---|---|
| Name | noble gases |
| Metal / Non-metal | non-metal |
| Reactive / Non-reactive | non-reactive |
Periods
Elements in the same period have the same number of electron shells.
For example, all the elements in period 3 will have 3 electron shells.
This can be seen by looking at their electronic configurations: Sodium (2.8.1), aluminium (2.8.3) and chlorine (2.8.7). Each configuration consists of 3 numbers.
