Hydrocarbon, any of a class of organic chemical compounds composed only of the elements carbon (C) and hydrogen (H). The carbon atoms join together to form the framework of the compound; the hydrogen atoms attach to them in many different configurations. Hydrocarbons are the principal constituents of petroleum and natural gas.
Use slab in a sentence. 1  a piece that is flat, broad, and fairly thick: a slab of concrete, a slab of bread.  any of the rough, outer pieces cut from a log, as in sawing it into lumber.
pillar. 1  a long, slender, vertical structure used to support a superstructure; column. 2  such a column standing alone as a monument. 3  anything like a pillar in form or function, as a formation of ore left standing as a support in a mine. 4  a person who is a main support of an institution, movement, etc.