In this post, we will list down a few important properties of metals and discuss them briefly.
Important Properties of Metals
- In general, metals have high densities
- In general, metals have high melting points and high boiling points
- In general, metals are good conductors of heat and electricity
- In general, metals are malleable (can be hammered into different shapes)
X-ray analysis shows that the atoms in most metals are packed as close together as possible. This arrangement is called close packing.
Melting and boiling points
High melting points and high boiling points suggest that there are strong forces holding the atoms together in metal crystals.
Chemists think that the outermost electrons in metal atoms move about freely. So, the metal consists of positive ions surrounded by a ‘sea’ of moving electrons.
As the electrons move about freely and are not localized in one position, they are described as delocalized electrons. The negative ‘sea’ of delocalized electrons attracts all the positive ions and so cements everything together.
These forces of attraction between closely packed atoms result in high melting points and high boiling points.
When a metal is heated, energy is transferred to the electrons. The electrons move around even faster and conduct the heat (energy) to other parts of the metal.
When a metal is connected to a battery in a circuit, freely moving electrons in the metal move towards the positive terminal. At the same time, electrons can be fed into the other end of the metal from the negative terminal. This flow of electrons through the metal forms the electric current.
The forces of attraction between ions and delocalized electrons in a metal are strong, but they are not rigid. When a force is applied to a metal, the layers of ions can ‘slide’ over each other. This is known as slip. After slipping, the ions settle into position again and the close-packed structure is restored.