__Sn(NO2)4 + __Pt3N4=__Sn3N4 + _ Pt(NO2)4. balance

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 think it is true since you can test the answer and can use observations to complete it.

lol for the pointsss