Giant covalent structure

This is the basis of the structure of diamond, which is made up of carbon atoms in tetrahedral units covalently bonded together into what is, in effect, a huge molecule. 

Very high m.p.. b.p. Insoluble in water. Graphite conducts, diamond does not. 

Giant metallic M.p., b.p. may be high (tungstenl or low (mercury). May react or corrode with water. All conduct electricity well. 

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This type of giant covalent structure is thermally very stable and has a very high melting and boiling points because of the strong covalent bond network (3D or 2D in the case of graphite). They are usually poor conductors of electricity because the electrons are not usually free to move as they can in metallic structures. 

Graphite has a giant atomic (or giant covalent) structure [1]. The bonding between atoms is covalent [1]. 

Predict the properties of silicon carbide (SiC). It has a giant covalent structure based on diamond. Find out about the uses of silicon carbide,... 

Silicon, also in period 3, has p orbitals significantly larger than those of oxygen. Their differences in size and energy mean that extensive overlap does not occur. Consequently silicon dioxide, Si02, has a giant covalent structure (see Chapter 4) where the bonds are -O-Si-O-bonds. No stable Si02 (0=Si=0) molecules are possible in the solid state. 

Eventually millions of carbon atoms are bonded together, in a giant covalent structure. This is part of it. 

There are several compounds which have giant covalent structures like that of diamond. Silica or sand is one of them. Like diamond, it is hard, has a high melting point, and does not conduct electricity. 

Group A—giant ionic structure Group B—giant covalent structure Group C—molecular structure... 

Some covalently bonded structures have a three-dimensional network of covalent bonds throughout the whole structure. We call these structures giant molecular structures or giant covalent structures. 

The element in the centre of Period 3, silicon, has the highest melting point because of its giant molecular structure (also called a giant covalent structure). Every silicon atom is held to its neighbouring silicon atoms by strong covalent bonds. However, its electrical conductivity is much lower than the metals at the start of the period because there are no delocalised electrons free to move around within its structure. Silicon is classed as a semimetal, or metalloid. 

Notice the high melting points of the giant ionic and giant covalent structures, leading to the use of ... 

Diamond has giant covalent structure [1] all bonds are strong / strong bonding in three dimensions/ lots of bonds joined together [1]... 

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