Answer the following question given this paragraph: 

Hardness helps determine how an element (especially a metal) might be used. Many elements are fairly soft (silver and gold, for example) while others (such as titanium, tungsten, and chromium) are much harder. Carbon is an interesting example of hardness. In graphite (the “lead” found in pencils) the carbon is very soft, while the carbon in a diamond is roughly seven times as hard.


Q: Although they differ vastly in hardness, pencil lead and diamonds both contain what element?


A:
carbon