Respuesta :
A closed economy is self-sufficient, meaning no imports are brought in and no exports are sent out, the goal being to provide consumers with everything they need from within the economy's borders. An example would be how Brazil's is an unusually closed economy as measured by trade penetration, with exports plus imports equal to just 27.6 per cent of GDP in 2013.
I think this is for economy not chemistry but one example of economy is no people can drive goods across places or get boats across globe but people need economy to live and without it it would be really hard because if you need something its not there its somewhere else and thats what the people in boats in big trucks deliver!