## negative Ep

Annie Chantasirivisal_4G
Posts: 114
Joined: Wed Sep 18, 2019 12:21 am

### negative Ep

Does anyone understand why Ep is always negative for interaction potential energy?

I missed Dr. Lavelle's explanation... why does a negative Ep lead to attractive force?

Posts: 52
Joined: Thu Jul 11, 2019 12:16 am
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### Re: negative Ep

I think it's just a matter of convention. From what I've read though, at least in the realm of electrostatics, potential energy is usually the work that must be done to move an object a certain distance. if the potential energy is negative, it's entirely possible that it means that no work has to be done for the two atoms to move together.

Jielena_Bragasin2G
Posts: 104
Joined: Sat Aug 24, 2019 12:18 am
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### Re: negative Ep

Ep is always negative due to it being an attractive force; similarly gravity, is negative and an attractive force, so gravity can be seen as analogous too Ep.

805422680
Posts: 103
Joined: Sat Sep 14, 2019 12:16 am

### Re: negative Ep

This is because the charges on both the atoms are different i.e. one is positive and the other is negative. When using the equation to calculate Ep, you are multiplying both the charges on the atoms (q1.q2/r^2). Since multiplying a negative by a positive, will always give you a negative answer, Ep is negative for attractive forces (as the charges have to be opposite for attraction to occur.

Nick Lewis 4F
Posts: 111
Joined: Wed Sep 18, 2019 12:18 am

### Re: negative Ep

I think Ep is always negative because when 2 molecules interact, it is usually a likely reaction when Ep is negative. It is likely to happen and when they interact, energy is released, hence the negative sign.

Daniel Yu 1E
Posts: 100
Joined: Sat Aug 24, 2019 12:15 am

### Re: negative Ep

Is Ep the measure of the strength of the bond or how much energy it takes to break the bond or are they the same thing?