Given that the formula of butane C4H10 the accepted value for the molar mass should be

carbon mass = 12.01g/mol

hydrogen mass = 1.01g/mol

4 carbon atoms and 10 hydrogen so

12.01 x 4 + 1.01 x 10

48.04g/mol + 10.10g/mol

= 58.14g/mol

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: