Carbon, as the compound carbon dioxide, gets some bad press for its effects on climate – and so it should! But that is pretty harsh on the element carbon (and the element oxygen for that point). Carbon is the fifteenth most abundant element in the Earth’s crust, and the fourth most abundant in the Universe. It is element 6 on the periodic table, meaning that it has four electrons in its outer shell. This means that it can form up to four chemical bonds simultaneously, hence compounds like methane (CH4) and carbon tetrafluoride (CF4). Carbon is an amazing element because it can form long chains that are the basis of all organic (living) molecules on Earth. It is the second most abundant element in the human body after oxygen.
Elements that exist in more than one physical form are called allotropes. There are two common allotropes of carbon. The first is graphite, which is a soft black solid used to make pencil leads and that forms the soot in your chimney. The other is diamond. Diamonds form over a few billion years as a result of lumps of graphite being squashed and heated by immense forces 200 km below ground. Graphite is one of the softest naturally occurring minerals, whereas diamond is the hardest (1600 times harder than graphite). Graphite is a good electrical conductor (unusual for a non-metal) but diamond is an insulator.
There are now some newer allotropes of carbon that have been formed in laboratories. The first of these is the Buckminster-Fullerene, or buckyball, which is a ball of 60 carbon atoms arranged in hexagons (similar to the design of a football). Secondly, there are carbon nanotubes that are only 1/50,000th of the width of a human hair (see animation) but are about 50 times as strong as steel, with only a quarter of the density. Thirdly we have graphene, which is a sheet of carbon just one atom thick. Graphene can now be cut into ribbons just a few atoms wide, which may have very interesting properties similar to the silicon used to build computer processors. Carbon has some advantages over silicon which means that it might be able to replace silicon in the next generation of super computers.
Graphene would prevent the heating effect that limits the size of most computer processors. The higher the frequency at which they operate, the higher the temperatures that develop. Graphene could also be used to make much more efficient photocells for turning light into electricity, build improved screens for laptop computers and games consoles (sheets of graphene are transparent), interact with fibre optic cables to produce super fast broadband connections or mobile phones with an even more impressive array of features.
Andre Geim and Konstantin Novoselov working at Manchester University won the 2010 Nobel Prize for Physics for their experiments with graphene.
Questions…
- What is the most abundant element in the Univese?
- What is the most abundant element in the Earth’s crust?
- Carbon is a non-metal element. What particular physical property does it have that makes it more like a metal element?
- Carbon dioxide shares a chemical property with many other non-metal oxides. What is it?
- Carbon is black in the form of graphite. Can you name a common chemical compound which is also black?
- Organic chemistry is essentially the study of the compounds of carbon. What biological process turns atmospheric carbon into organic carbon?
1. Hydrogen
2. A gas, presumably oxygen because of oxides
3. Could not answer so googled it (it also conducts)
4. They are acidic in nature
5. Copper Oxide
6. Compression
an interesting “lesson” Sir!
Q1 – yes
Q2 – it is oxygen for the reason you suggest. Water & sand are both oxides and most metals appear as oxygen. Why did you assume it was a gas? It is mostly not found in the form of a gas. Gas, liquid and solid are relative terms because they depend upon temperature. Silicon, the second most abundant element is a solid at room temperature and aluminium is third most abundant element.
Q3 – Read the paragraphs carefully, it said “Graphite is a good electrical conductor (unusual for a non-metal) but diamond is an insulator.” so you should not have needed to resort to Google.
Q4 – good. Non-metal oxides tend to be acidic whereas metal oxides are basic.
Q5 – excellent but try not to give chemicals capital letters
Q6 – is compression a biological process? This is not a question about diamond formation, it is about how carbon in the atmosphere becomes carbon in living things.