Structure and Bonding of 5 different materials (Chemistry) - Assignment Example

Silicon dioxide forms a giant covalent structure/lattice, extending in all the 3 dimensions. Each silicon atom is covalently bonded to 4 oxygen atoms. A large number of covalent bonds are present. This renders it high strength and hardness. A huge amount of thermal energy is needed to overcome these forces and cause melting of silicon dioxide, which hence explains the high melting point. Similarly, energy of dissolution when dissolved isn’t high enough to make it soluble in either of the polar or non polar solvents.

Since the atoms are rigidly fixed in their positions with no free electrons, silicon dioxide is not a conductor of electricity as such but behaves as a semi conductor. Carbon dioxide is a gaseous compound found in the atmosphere at concentrations of 0.3%. Carbon dioxide has a molecular structure where each carbon atom is covalently bonded to two oxygen atoms as shown in the figure. As the Mr of carbon dioxide is a mere 44, weak intermolecular forces (instantaneous dipole-induce dipole forces) exist between the molecules of the carbon dioxide (BBC Higher Bitesize, 2009).

These are easier to overcome and therefore, carbon dioxide has a very low boiling point, such that it is present in the gaseous state at room temperature. Having no free electrons, it is a non-conductor of electricity. It can dissolve in water and other solvents owing to solute solvent interactions. Copper is metallic in nature, which is widely used in electrical wires owing it its high conductivity. It is hard yet malleable and ductile, has a high melting and boiling point and is insoluble in any kind of solvent.

Metallic bond is formed the metal atom looses an electron to become a positively charged ion (Jim, 2010). The electrons (delocalised) form a sea of electrons which hold the positive metal ions together in a giant structure. These strong forces of attraction developed between the delocalised electrons and the metallic ions give copper it’s high melting and boiling point. Moreover, it is the very same electrons that are free to move inside the metallic structure giving copper its good electrical properties (Green planet, 2011).

Same electrons also act as thermal carriers making copper a good thermal conductor as well. The layers of atoms have the ability to move/slide over each other when a force is applied. This gives copper good malleability and ductility characteristics. However, this movement of layers is hindered by the grain boundaries which impart good hardness to copper as well. In water, each hydrogen atom is bonded to two oxygen atoms. Owing to the large difference in the electro negativity of the two, a partial positive charge appears on hydrogen while a partial negative charge is appears on oxygen.

Furthermore, there exists a lone pair of electrons on the oxygen atom. When two water molecules come closer, a hydrogen bond is developed between the lone pair of electrons and the partially positively charged hydrogen atom (MDL, 2008). This is a strong bond which raises the boiling point of hydrogen to 100oC. The absence of free electrons makes pure water a non-conductor of electricity and a bad thermal conductor. Being polar in nature, water is insoluble in organic solvents. Caesium Chloride forms a giant ionic lattice structure.

Each caesium atom is bonded to eight chloride atoms through ionic bonds. Ionic bond exists because of large difference of electro negativities of the two atoms (Jim, 2010). The large number of strong ionic bonds