How many electrons will an iodine atom donate or accept, based on its number of valence electrons

Iodine has seven valence electrons.

Explanation:

Valence electrons of an atom are located in the outermost shell of the atom and participate in bonding. 

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current

increased stability in the completion of fluorine's outer shell.