I have a question.

1.We all know that electron is negative and the nucl is positive and that they attract to each other. My question is why the electron ORBITS the nucl? What are the fources influencing that behavior of the electron?

Thank you

The answer lies in the understanding of the quantum model of the atom which is by far the most accurate to date. The classical model of the electron orbiting around the nucleus like the Earth does around the sun is an incorrect view. You can read about this at How Stuff Works or this question has been asked before.

 

http://www.scienceforums.net/forums/showthread.php?t=10263

http://science.howstuffworks.com/atom8.htm

basically the electron orbits because it is less massive than the nucleus which is at least 1439 times heavier than the sum of the electrons.

As mezarashi points out, the orbits are not planetary in nature. But you have an electrostatic force of attraction between the two, and the Heisenberg Uncertainty Principle precludes the electron from being bound to a region the size of a nucleus.