Why all goals cannot be met in economics?

The in the very definition of 'economics' explains why. Since, economics is a  social science that studies human behaviour, is a relationship *BETWEEN* ends and scarce means..

'ends' that is goals, and "scarce means" referred to the resources. So that is the economic problem, that there are *unlimited* wants but scarce resources. So the answer to this question is just: All goals cannot be reached because there are unlimited "goals", and few/limited resources.

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf