Can a closed system gain particles

How do you determine the percent yield of a chemical reaction

How do you convert celsius to kelvins

How long could you survive without electricity? what parts of your life would be affected by loss of electricity? should you prepare for an electricity outage, and if so, how would you prepare? what backup system could your family or community install to generate limited amounts of electricity during an outage? how does this system create an electric force field and generate electric current?