What is the goal number of electrons to be achieved in the outermost energy shell for a chemical bond to occur?

The answer is; 8

This is also referred to as the octet rule. Inert elements tend to have an 8 election configuration in their outermost shell while other elements react to achieve this electron configuration. This is determined by their  position in the periodic table. However, there are exceptions; Helium has a 2 stable electron configuration in the outermost shell while transition metals have stable 18-electron configuration.;

air, water, heat and noise pollution can all be caused by producing and using technology. consuming resources - non-renewable resources, including precious metals like gold, are used to make technology