What is indicated by the pro-prefix?
the molecule is an alkene
the molecule has 3 carbon atoms
the molecule is a stereoisomer
the molecule is saturated with hydrogen atoms

Answer(28.02g/mol);

Following are the  advantages of the parametric equations: 1) they can be used to graph curves that are not functions, like the unit circle.2) the parameter can be used to represent the quantity that is  useful to  provide us with better information about the graph.3)  it is useful to convert between rectangular equations and parametric equations.with specific reference to chemistry,  parametric equations are employ for solving hydrogen and hydrogen-like ions, quantum mechanically. herein, cartesian coordinates are converted in spherical polar coordinates. the solution obtained, when plotted on spherical polar graph paper, provides visualization of atomic orbital such as s,p,d and f. 

The answer would have to be  reduce human impact on the environment