Very high melting points – this is because a lot of strong covalent bonds must be broken. Graphite, for example, has a melting point of more than 3,600°C. Variable electrical conductivity – diamond does not conduct electricity, whereas graphite contains free electrons so it does conduct electricity.
Why do diamond and graphite both have high melting points?
Both diamond and graphite have a giant molecular structure. The carbon atoms are held together by strong covalent bonds which require high temperatures to break. This causes diamond and graphite to have high melting points.
What do diamond and graphite both contain?
Both diamond and graphite are made entirely out of carbon, as is the more recently discovered buckminsterfullerene (a discrete soccer-ball-shaped molecule containing carbon 60 atoms). The way the carbon atoms are arranged in space, however, is different for the three materials, making them allotropes of carbon.
Why is diamond hard and graphite is not note that diamond and graphite are both composed of carbon atoms only explain your answer in terms of their crystal structure and bonds?
This allows layers of carbon to slide over each other in graphite. On the other hand, in diamond each carbon atom is the same distance to each of its neighboring carbon atoms. In this rigid network atoms cannot move. This explains why diamonds are so hard and have such a high melting point.
Why is diamond hard and has a high melting point?
Diamond has a very high melting point because a large amount of energy is needed to overcome the many strong covalent bonds. There are no electrons or other charged particles that are free to move so diamond does not conduct electricity.
Why is diamond hard but graphite soft?
Diamond is harder than graphite because each of its carbon atoms form four covalent bonds in a tetrahedral structure and also due to the presence of strong covalent bonds in it. … Therefore, diamond is hard but graphite is soft and slippery even though both have carbon present in them.
What makes graphite a good lubricant?
The delocalised electrons are free to move through the structure, so graphite can conduct electricity. … The layers in graphite can slide over each other because the forces between them are weak. This makes graphite slippery, so it is useful as a lubricant .
Which is more stable diamond or graphite?
At normal temperatures and pressures, graphite is only a few eV more stable than diamond, and the fact that diamond exists at all is due to the very large activation barrier for conversion between the two. … So diamond is said to be metastable, since it is kinetically stable, not thermodynamically stable.
Which one is harder a diamond or a graphite?
Graphite is very soft and has a hardness of 1 to 2 on this scale. Diamonds are the hardest known natural substance and have a hardness of 10.
Why is diamond so hard?
The outermost shell of each carbon atom has four electrons. In diamond, these electrons are shared with four other carbon atoms to form very strong chemical bonds resulting in an extremely rigid tetrahedral crystal. It is this simple, tightly-bonded arrangement that makes diamond one of the hardest substances on Earth.
What’s harder than diamond?
Moissanite, a naturally occurring silicon-carbide, is almost as hard as diamond. It is a rare mineral, discovered by the French chemist Henri Moissan in 1893 while examining rock samples from a meteor crater located in Canyon Diablo, Arizona. Hexagonal boron-nitride is 18% harder than diamond.
What are the similarities and differences between graphite and diamond?
Diamond has a tetrahedral structure and is the hardest material known to man. There are strong covalent bonds between carbon atoms and each carbon atom is bonded to 4 other carbon atoms. Graphite has a hexagonal layered structure and each carbon is bonded via strong covalent bonds to 3 other carbon atoms.
What is the relationship between diamond and graphite?
Diamond and graphite are both allotropes of carbon. Allotropes are basically different forms of the same element. The only difference is the structure and arrangement of how the carbon atoms are oriented.
What is the melting point of diamond?
The ultimate melting point of diamond is about 4,027° Celsius (7,280° Fahrenheit).
What does diamond have a high melting point?
Diamond has a giant covalent structure. Each carbon atoms form four strong covalent bonds with the other carbon atoms. As there are many strong covalent bonds, a lot of thermal energy is needed to break these bonds, thus diamond has a very high melting point.
Is Diamond soluble in water?
Diamond is insoluble in water. It does not conduct electricity. Every atom in a diamond is bonded to its neighbours by four strong covalent bonds, leaving no free electrons and no ions .