Question

Why do elements that make positive ions occur on the left side of the periodic table while those that make negative ions occur on the right?

Answer 1

Because on the right they want and gain electron while on left they give

Answer 2

Metals tend to lose electrons in order to attain an e-configuration isoelectronic with a noble gas; or gain stability in the form of a half or full outer subshell. Non metals gain electrons to gain an isoelcetronic noble gas structure.