The weak Galerkin (WG) finite element method is an effective and flexible general numerical technique for solving partial differential equations. The novel idea of weak Galerkin finite element methods is on the use of weak functions and their weak derivatives defined as distributions. Weak functions and weak derivatives can be approximated by polynomials with various degrees. Different combination of polynomial spaces generates different weak Galerkin finite elements. The purpose of this paper is to study stability, convergence and supercloseness of different WG elements by providing many numerical experiments recorded in 31 tables. These tables serve two purposes. First it provides a detail guide of the performance of different WG elements. Second, the information in the tables opens new research territory why some WG elements outperform others.