An atom of element x has one more shell of electrons than an atom of beryllium, but it has one less valence electron than beryllium. which element is element x?

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation:

it's c (engineer's do their work with mechanical stuff not on any living being)