Silicon

\Sil"i*con\, n. [See Silica.] (Chem.) A nonmetalic element analogous to carbon. It always occurs combined in nature, and is artificially obtained in the free state, usually as a dark brown amorphous powder, or as a dark crystalline substance with a metallic luster. Its oxide is silica, or common quartz, and in this form, or as silicates, it is, next to oxygen, the most abundant element of the earth's crust. Silicon is characteristically the element of the mineral kingdom, as carbon is of the organic world. Symbol Si. Atomic weight 28. Called also silicium. Used in computer chips, transistors, solar cells, rectifiers, and other electronic solid-state devices

Cortex

n 1: the layer of unmyelinated neurons (the gray matter) forming the cortex of the cerebrum [syn: cerebral cortex, cerebral mantle, pallium] The extensive outer layer of gray matter of the cerebral hemispheres, largely responsible for higher brain functions, including sensation, voluntary muscle movement, thought, reasoning, and memory.