Describe the reactivity of the halogens, Cl2, Br2, and I2 compared to their relative position in the periodic table.

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:

i belive it is water