What does the octet rule state that explains why atoms bond?

An atom bonds to have eight valence electrons to become stable. ... The third shell would be empty so that the eight electrons in the second level would be outermost after the atom loses one electron.

Explanation:

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: