Need it is physical science only number 8 & 9

#8 
Chemical energy and nuclear energy are both forms of potential energy.
We discover this if we actually READ the discussions of each type of
energy, on the left side of the sheet.  Over there, it tells us that chemical
energy and nuclear energy are both STORED energy ... ready to do work
when we release it from storage and start using it.  That's potential energy.

#9
a). electromagnetic, heat, chemical
b). electromagnetic, heat, chemical
c). electromagnetic, heat
d). mechanical, electromagnetic, heat, chemicale). mechanical
f). electromagnetic, heat, nuclear

The answer is 4f======since electrostatic force is given by    we let f be the electrostatic force when  r = 1 m    if we let  denote the electrostatic force when the distance is decreased so that r = 0.5m, then    we established earlier that f = kq₁q₂. therefore    the force will now be 4f.