Carbon
The atomic number is 6 and the mass number is 12.001
Charcoal
The main ingredient of the charcoal is carbon. Carbon compounds store lots of energy and is good at holding onto heat. That's why it's used for charcoal.
Graphite
Graphite is a special type of carbon in your pencil this is what we use to write with.
Diamonds
Diamonds are a big chunk of carbon. After a very long time and carbon is left in a very high pressure area, all of the atoms are pushed together to form a crystal. That crystal is called a diamond.