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.
boulder definition: The definition of a boulder is a large, smooth rock. (noun) When you build a retaining wall and use a large rock in the wall, this rock is an example of a boulder. A rock that has been detached from the earth by erosion or for ot...