From the relative atomic mass of each element, it is possible to determine each element's molar mass by multiplying the molar mass constant (1 g/mol) by the atomic weight of that particular element. The molar mass value can be used as a conversion factor to facilitate mass-to-mole and mole-to-mass conversions.
A. The negative ionic radius is larger than the neutral atomic radius.
Solar Power, Microbial fuel cell. These two and I am sure other ways as well Solar power as you guess use the sun as a power energy source with non-waste and long lasting use. Microbial fuel uses the bacteria aka decomposers turn the sugars, nutrients into rich soil while also releasing electrons back into the soil and can be used as a energy source.