Structure of Metals
The structures of pure metals are simple to describe since the atoms that form these metals can be thought of as identical perfect spheres. More specifically the metallic structure consists of 'aligned positive ions' (cations) in a "sea" of delocalized electrons. This means that the electrons are free to move throughout the structure, and gives rise to properties such as conductivity.
What are different types of bonds?
A covalent bond is a bond that is formed when two atoms share electrons. Examples of compounds with covalent bonds are water, sugar and carbon dioxide.
Ionic bonding is the complete transfer of valence electron(s) between a metal and non-metal. This results in two oppositely charged ions which attract each other. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion. An example of an Ionic bond would be salt (NaCl).
Metallic bonding is the result the electrostatic attractive force that occurs between conduction electrons (in the form of an electron cloud of delocalized electrons) and positively charged metal ions. It may be described as the sharing of free electrons among a lattice of positively charged ions (cations). Metallic bonding accounts for many physical properties of metals, such as strength, ductility, thermal and electrical resistivity and conductivity, opacity, and luster.
Delocalized Moving electrons in Metals --
It is the free movement of electrons in metals that give them their conductivity.
Metals contain free moving delocalized electrons. When electric voltage is applied, an electric field within the metal triggers the movement of the electrons, making them shift from one end to another end of the conductor. Electrons will move toward the positive side.
Metal is a good conduction of heat. Conduction occurs when a substance is heated, particles will gain more energy, and vibrate more. These molecules then bump into nearby particles and transfer some of their energy to them. This then continues and passes the energy from the hot end down to the colder end of the substance.
Why do metals conduct heat so well?
The electrons in metal are delocalised electrons and are free moving electrons so when they gain energy (heat) they vibrate more quickly and can move around, this means that they can pass on the energy more quickly.
Which metals conduct the best?
Silver has a larger atomic radius (160 pm) than gold (135 pm), despite the fact that gold has more electrons that silver! For a reason for this see the comment below.
Note: Silver is a better conductor than gold, but gold is more desirable because it doesn't corrode. (Copper is the most common because it is the most cost effective)
SOURCES AND READERS CHOICES --