Answer: (2) > (1) > (3) > (4)
Explanation:
(1) a +1 charge and a -1 charge separated by 200 pm:
The potential energy in this case will be,
(2) a +1 charge and a +1 charge separated by 100 pm:
The potential energy in this case will be,
(3) a +1 charge and a -1 charge separated by 100 pm:
The potential energy in this case will be,
(4) a +2 charge and a -1 charge separated by 100 pm:
The potential energy in this case will be,
So, the order from <u>highest</u> potential energy <u>to lowest</u> potential energy is:
(2) > (1) > (3) > (4)