How does the structure of the giant covalent compound help us to explain their properties?

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How does the structure of the giant covalent compound help us to explain their properties?


Giant covalent structure

The majority of covalent structures have fixed number of atoms in a discrete molecule. A covalent structure is held together by strong covalent bonds but have a weaker intermolecular force between them. While a giant covalent structure contains a lot of non-metal atoms, the atoms are arranged in a giant 3 dimensional lattice shape with different layers. The main example of giant covalent structures are Diamond and Silicon.

Diamond
Diamond is mainly seen as piece of luxury. Diamond has a bond angle of 109.5o .However, its structure is made out of carbon atoms that are strongly bonded by covalent bonds in a tetrahedral structure. As a result diamond as a high melting and boiling point because there is more energy needed to breakdown the atoms in a diamond structure. Diamond also, is also a bad electricity conductor. In a diamond structure there’s no delocalized electrons. Diamond is also the strongest natural element.

Silicon
In a silicon structure, each atoms is bonded to four other atoms in a tetrahedral arrangement. The electrons in  silicon are put in a fixed position where they cannot move within a structure. Silicon is only a poor electricity conductor at low temperature .

How does the structure of the giant covalent compound help us to explain their properties?

Well if we look at the structure of diamond for example and we want to now why does diamond is a bad electricity conductor its because electrons are all bonded strongly together and as no delocalized electrons.To be a good electricity conductor an element must have its electrons moving freely from one atom to another. Another aspect of diamond structure that help us  explain why diamond is hard is its structure itself. Diamond as four carbon atom that are covalently bonded with four other carbon atom that is why there is more energy needed to breakdown diamond resulting in diamond being hard.

By: Kenneth

Reference


Kognity IBDP Chemistry SL Section 4.3.5 and 4.3.6




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