What mass, in grams,
of oxygen is needed to react
with 1.46 grams of methane, CH_?
CH4 + O2 CO2 + H2O

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: