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.
1 Concrete slab, a flat concrete plate used in construction. 2  Slab (casting), a length of metal. 3  Slab (geology), that portion of a tectonic plate that is subducting.  Slab pull force, the tectonic plate force due to subduction.