Diamond and graphite
Carbon is an A substance made of one type of atom only. in A vertical column in the periodic table containing elements with similar chemical properties. 4 (IUPAC group 14) of the A tabular representation of all known elements in order based on atomic number, eg all the noble gases are found on the right of the periodic table.. Each carbon atom can form four A bond between atoms formed when atoms share electrons to achieve a full outer shell of electrons.. This means that carbon The smallest part of an element that can exist. can form families of similar compounds that have:
- chains
- rings
Compounds that contain carbon atoms, joined by covalent bonds to other atoms (including other carbon atoms). are substances that contain carbon. There is a vast array of natural and A material made by a chemical process, not naturally occurring. organic compounds because of the ability of carbon to form four covalent bonds. Carbon can also form giant covalent structures, including A form (allotrope) of pure carbon in which all the atoms are bonded to four others in a giant tetrahedral network structure which is very strong. Diamond is the hardest known natural substance, has a very high melting point and does not conduct electricity. and A form of pure carbon in which all the atoms are bonded to three others in giant sheets which can slide over each other..
Diamond
Structure and bonding
Diamond has a giant A covalent substance is a molecule containing one or more covalent bonds (shared pairs of electrons). structure in which:
- each carbon atom is joined to four other carbon atoms by covalent bonds
- the carbon atoms have a regular A regular grid-like arrangement of atoms in a material. arrangement
- there are no free Subatomic particle, with a negative charge and a negligible mass relative to protons and neutrons.
Properties and uses
The rigid structure, held together by strong covalent bonds, makes diamond very hard. This physical The characteristics of something. In chemistry, chemical properties include the reactions a substance can take part in. Physical properties include colour and boiling point. makes diamond useful for cutting tools, such as diamond-tipped glass cutters and oil rig drills.
Graphite
Structure and bonding
Graphite has a giant covalent structure in which:
- each carbon atom is joined to three other carbon atoms by covalent bonds
- the carbon atoms form layers with a hexagonal arrangement of atoms
- the layers have weak forces between them
- each carbon atom has one non-bonded outer electron, which becomes Electrons that are not associated with a particular atom, eg in a metal, outer electrons can be free to move through the solid.
Properties and uses
The delocalised electrons are free to move through the structure, so graphite can To allow electricity, heat or other energy forms to pass through. electricity. This makes graphite useful for A conductor used to establish electrical contact with a circuit. The electrode attached to the negative terminal of a battery is called a negative electrode, or cathode. The electrode attached to the positive terminal of a battery is the positive electrode, or anode. in batteries and for electrolysis.
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 A lubricant is anything which reduces the friction between two surfaces..