A vertical column in the periodic table. Members of a group typically have similar properties and electron configurations in their outer shell. Period. A horizontal row in the periodic table. The atomic number of each element increases by one, reading from left to right.
circumference - the length of the closed curve of a circle. length - the linear extent in space from one end to the other; the longest dimension of something that is fixed in place; the length of the table was 5 feet. sextant - a unit of angular distance equal to 60 degrees.
Circumscribed circle, C, and circumcenter, O, of a cyclic polygon, P. In geometry, the circumscribed circle or circumcircle of a polygon is a circle which passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. A polygon which has a circumscribed circle is called a cyclic polygon (sometimes a concyclic polygon, because the vertices are concyclic).