Since the metal atoms have all lost their valence electrons, they are now all identical to cations. However, because they are not associated with ionic bonding, these cations have a special name. The cations within a metallic solid are known as Kernels.

The mechanism that holds a metallic bond together is the attraction between the positive kernels and the negative electron sea. The strength of the metallic bond is derived primarily from the charges in the system.

  • The larger the magnitude of the positive charge on the metallic nuclei, the greater the strength of the metallic bond.
  • The greater the number of valence electrons contributed to the electron sea, the greater the strength of the metallic bond.

Metallic bonds are omnidirectional. They do not have any geometric requirements which need to be fulfilled. Think of the marbles surrounded by water, in a box. The marbles can be pushed anywhere within the box and the water will follow them, always surrounding the marbles. Because of this unique property, metallic bonds can maintain their existence when pushed and pulled in all sorts of ways. As a result, metals are known for their flexibility -- thus they are malleable and ductile.

  • If a metal is subjected to a force, the kernels can slide around on the layer of electrons.
  • As the kernels move to new positions, the bonds will not break, because of their omnidirectional nature.
In addition to being malleable and ductile, they are also very good conductors of electricity. Electricity depends upon the flow of electrons. Whenever electrons can flow easily through a structure, then that structure is said to be a good electrical conductor. Clearly, the very fluid nature of the electron sea allows it to be a very good electrical conductor. Because of this quality, metals are usually used in the electronics industry.

Metals are also known as being good conductors of heat, or thermal conductors. Heat is kinetic energy. In order for a substance to conduct heat, it must be able to transmit kinetic energy.

  • If heat is applied to one side of a piece of metal, then the kernels will start to vibrate. Because they are so loosely held into the crystal structure, they will be able to vibrate freely.
  • With the increase in the amount of their vibration, they will run into the kernels located next to them. That will start more kernels to vibrate.
  • In this way, the process continues until all of the kernels in the system are vibrating.

Any material that has highly rigid structures because of strong, rigid bonding will not have the freedom of motion that is needed for the transmission of the kinetic energy.

While metals are highly regarded because of their unique qualities, they are also, generally, not useful in their pure forms. The very qualities that make them unique can also make them useless. They are too soft and malleable. So, much effort has been put into finding ways to keep the basic metallic qualities, but modify them so that they are not so extreme.

  • The introduction of a non-metallic element into a metal will cut down on malleability and ductility. Why?

Anything which diminishes the electron sea will reduce malleability and ductility.

  • The introduction of a non-metallic element into a metal will cut down on electrical conductivity. Why?

Anything which diminishes the electron sea will inhibit the easy flow of electrons.

  • The introduction of a non-metallic element into a metal will cut down on thermal conductivity. Why?

Anything which introduces rigid bonding into the metal will restrict the ability of the kernels to vibrate. With this loss of vibration, the system will not be readily able to conduct heat.