Metallic bonding

Metallic Bond

results when metallic atoms combine to form a metallic compound. A metal is a rigid framework of cations immersed in a ‘sea’ of electrons that serve as the cement holding the three-dimensional cationic network together.  Bond found in metals; holds metal atoms together very strongly.

Metal properties

Metals are solid at room temperature, except mercury, which is liquid. Metals have a very high melting point. Metals are shiny when they cut. Metals are good conductors of heat and electricity.Metals are usually strong & malleable so they can be hammered into shape. 

Columns one through three

Electron donors.

Nonmetals columns five through seven

Electron receiver.

Structure of Metals

Metallic atoms have low electronegativities (lose their outer shell electron easily). Once a metallic atom loses its outer shell electron it becomes a positively charged cation. 

Structure of metals(physical)

Metals are grouped close together in an organized pattern

(crystal lattices – metallic lattice structures). A lattice is a regular arrangement of

particles, whether these are atoms, ions or molecules. metallic lattice structures: made

up of an array of cations. Overlapping energy levels. 

Structure of metals(intramolecular)

The electrons from each metallic atom are found in a

common pool and are free to move between all the cations: Delocalized electrons. Electrons are not shared or transferred. Electrostatic forces of attraction between the positively charged cations and the negatively charged electrons hold the lattice together. A metal is a rigid framework of cations immersed in a ‘sea’ of electrons that serve as the cement holding the three-dimensional cationic network together. 

Properties of Metals(bonding)

The Lattice structure of metals explains their key properties. Particles tightly bound together (strength). Electron’s sea is always moving- flexible structure. Metals have a crystalline lattice structure.

Luster

due to mobile electrons within the lattice being able to reflect light causing the metal to shine. 

Conduction of heat

electrons are able to gain kinetic energy in hotter areas of the metal. Mobile electrons are able to quickly transfer the energy to other parts of the metal lattice because of their freedom of movement. 

Conduction of electricity

When an electric field is applied to a metal, one end of the metal becomes positive and the other becomes negative. The movement of electrons is an electric current. The structure allow mobile electrons to move from the negative pole to the positive pole.

Melting/Boiling point and hardness

high melting/boiling points and hardness of metals indicate strength of the metallic bonding. Increases with an increase in the number of valence electrons, since there is a greater attractive force between the CATions and the electrons.

Density

most metals have relatively high densities because metallic lattices are close-packed.

Metals

available in pure or alloy form.Pure Metals such as pure aluminium or pure copper, contain only one type of metal. They are not mixed with any other metal. Alloys are a mixture of two or more pure metals. Alloys tend to have better strength properties than pure metals. Alloys and pure metals often have special physical properties.

Alloys

Mixtures of two or more elements, at least one of which is a metal. Made by melting, mixing, then cooling the metals. May contain non-metals like carbon. Properties are superior to their components. Solid. Do not chemically react. Form molecular bonds. Substitutional alloys. Similar size atoms – replacement Interstitial alloys. Different size atoms – smaller ions fill interstices (spaces between atoms).