The ability to do work is

matter

energy

molecules

I uploaded the answer to a file hosting. Here's link:

cutt.ly/tz3yDpb

energy

energy is the reason why people can do things

in theory, limestone is composed principally of the compound calcium carbonate - caco3, but in reality this compound is deposited in conditions involving a number of other compounds as impurities so it ends up being a mixture of many compounds.

hope this : -)

tony (lordcaos066)