Potential energy curve of a molecule

In summary, the potential energy increases when two atoms are put closer to each other than the equilibrium bond distance, while it decreases when they are put closer to each other (but still farther than the equilibrium bond distance). This is due to the fact that repulsion causes an increase in energy, while attraction causes a decrease in energy. This is not always the case, as the effects can be opposite depending on the direction of movement. For example, in a system of two opposite charges, bringing them closer together will decrease the system's energy, while separating them will increase the system's energy. Therefore, the statement that "attraction always causes a decrease in energy" is incorrect.
  • #1
freedom856
12
0
Does anyone tell me why the potential energy increase(becomes more positive) when two atom put closer to each other which is smaller than the equilibrium bond distance while potential energy decrease(becomes more negative) when two atoms put closer to each other (which is close to equilibrium bond distance (faraway to equilibrium bond distance)

That is why repulsion causes energy increase and attraction causes energy decrease?

Thank you
 
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  • #2
your question is itself being answered by yourself...:-p
 
  • #3
i want to ask why repulsion will cause energy increase and attraction will causes energy decrease, Do you understand?
 
  • #4
Potential energy is by definition minus the integral of force over distance, or force always points in the direction of decreasing potential energy.
 
  • #5
freedom856 said:
i want to ask why repulsion will cause energy increase and attraction will causes energy decrease

This is not true as asked. Both can be seen as energy increase (decrease) depending on whether distance grows or goes down. As repulsion is opposite of attraction, nothing strange that effects are opposite when moving in the same direction.
 
  • #6
Borek said:
This is not true as asked. Both can be seen as energy increase (decrease) depending on whether distance grows or goes down. As repulsion is opposite of attraction, nothing strange that effects are opposite when moving in the same direction.

can you give some example to me for what you said? thank you
 
  • #7
If you have two different charges, they attract each other. Separating them means doing work on the system, and system energy increases. However, if you allow them to get closer, energy of the system decreases. So, you have a system of attracting charges, in one cases energy goes up, in other energy goes down. Clearly statement "attraction causes decrease of the system energy" is wrong.
 

Related to Potential energy curve of a molecule

1. What is a potential energy curve of a molecule?

A potential energy curve of a molecule is a graphical representation of the potential energy of a molecule as a function of its atomic separation. It shows the potential energy of the molecule at different bond lengths, providing insight into the stability and bonding of the molecule.

2. How is a potential energy curve of a molecule created?

A potential energy curve of a molecule is created by performing calculations using quantum mechanics methods. These calculations determine the potential energy of the molecule at different bond lengths, which can then be plotted on a graph to create the potential energy curve.

3. What information can be obtained from a potential energy curve of a molecule?

A potential energy curve of a molecule provides information about the stability and bonding of the molecule. It can also show the presence of any potential energy barriers or wells, which can affect the molecule's reactivity and properties.

4. How does potential energy affect the behavior of a molecule?

Potential energy affects the behavior of a molecule by influencing its stability and reactivity. A molecule with a higher potential energy at a certain bond length is less stable and may be more reactive compared to a molecule with a lower potential energy at the same bond length.

5. Can a potential energy curve of a molecule change?

Yes, a potential energy curve of a molecule can change depending on external factors such as temperature, pressure, and the presence of other molecules. These changes can affect the bond lengths and potential energy of the molecule, altering its stability and reactivity.

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