Technician a says when a battery is charging, it changes chemical energy into electrical energy. technician b
says when a battery is being discharged, it changes electrical energy into chemical energy. who is correct?
a. a only
c. both a and b
b. b only
d. neither a nor b

On solidification from a melt, the polymer polyethylene forms a semi-crystalline spherulite structure. (i) sketch an individual spherulite and label the amorphous and crystalline regions. (ii) draw a schematic to show the changes in specific volume with temperature during cooling from the melt, comparing it to the theoretical extremes of fully crystalline and fully amorphous (indicate tm and tg)