# Decreasing Energy due to attraction

## Recommended Posts

Why does the energy of a system decrease when two charged particles attract each other?

##### Share on other sites

Its actually about Book - keeping. It is the definition(agreement) of Energy.

do you why the potential energy of an object decrease as its height from earth decrease.

##### Share on other sites

it really depends on the system

##### Share on other sites

I am not sure what you mean by this question.

Do you mean the potential energy?

Do you mean that the potential energy is different for two particles that have no charge and two that do?

Do you mean the potential or total or kinetic energy changes if two charged particles mocve towards each other?

or What?

##### Share on other sites

Ok I am being specific why I asked the question.

Electrons have negative energy values. At infinite distance(out of boundary of atom) the electron is considered to have no energy at all as it isn't attracted by the protons. I understood this.

But as it moves closer to the nucleus, it is attracted by the protons and energy is released and energy of system decreases. Why?

##### Share on other sites

Ok I am being specific why I asked the question.

Electrons have negative energy values. At infinite distance(out of boundary of atom) the electron is considered to have no energy at all as it isn't attracted by the protons. I understood this.

But as it moves closer to the nucleus, it is attracted by the protons and energy is released and energy of system decreases. Why?

It depends on what "why" represents.

Energy is released, as you say. If you release energy, the energy you have goes down. That's how we balance the books: energy is conserved.

Another way of answering is: the force is attractive. The energy involved is the work; the incremental work is defined as dW = Fdx. Since the force is attractive the work is negative. As the electron approaches the proton the potential energy decreases (the work) but since energy is conserved, the kinetic energy increases. In atoms, though, there is the release of a photon, which is reduction of the energy of the system.

##### Share on other sites

OKie.. Got it..
I wanted the 2nd answer! This forum is awesome!
Bookmarked it!

## Create an account

Register a new account