An element in group two has two valence electrons. when forming a chemical bond it will most likely (gain, lose, share, or not react) electrons

Lose electrons - electrons want to fill their outer valence shell, so sometimes instead of gaining it is easier to lose some and have a filled outer shell

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: