Methylphenidate is a commonly prescribed psychostimulant and works by increasing the activity of the central nervous system. It produces such effects as increasing or maintaining alertness, combating fatigue, and improving attention. The short-term benefits and cost effectiveness of methylphenidate are well established.
(image copied from here). 1  Igneous Rocks: form by crystallizing melted material (magma). 2  They can form either on the surface (extrusive igneous rocks), or deep in the crust (intrusive or plutonic igneous rocks).
Best Answer: Igneous rocks are formed when magma (or molten rocks) have cooled down and solidified. Sedimentary rocks are formed by the accumulation of other eroded substances. Metamorphic rocks are formed when rocks change their original shape and form due to intene heat or pressure.Igneous rocks are commonly found inside the Earthâs crust or mantle.Sedimentary rocks are usually found in water bodies. Metamorphic rocks are found on the Earthâs surface.edimentary rocks are formed by the accumulation of other eroded substances. Metamorphic rocks are formed when rocks change their original shape and form due to intene heat or pressure.