4. A chemical reaction has the equation 2NaCl (aq) + F2 (g) + 2NaF (s) + Cl2 (g). What type of reaction occurs between NaCl and F2? A. Double displacement
B. Single displacement
C. Synthesis
D. Decomposition

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: