# Coulomb's Law and electron placement

• soul5
In summary, to balance the weight of the electron with the electric force, it must be placed at a distance of -0.35*10^-9C from the point charge.
soul5

## Homework Statement

A point charge of -0.35nC is fixed at the origin. Where must an electron be placed in order for the electric force acting on it to be exactly at it's weight.

Fe=Kqq/d^2

## The Attempt at a Solution

All I know is that n is an exponential value of -9

soul5 said:

## Homework Equations

Fe=Kqq/d^2
Better write that as:
$$F_e = \frac{k q_1 q_2}{d^2}$$

## The Attempt at a Solution

All I know is that n is an exponential value of -9
That's q_1. The other charge will be the electron. What's the charge and mass of an electron? (Look it up!)

What must the total force on the point charge be when the electric force balances the weight (gravitational force)? You wrote down the formula for electric force, which comes from Coulomb's Law. Do you know how to use Coulomb's Law? If you do, what is the electric force on the point charge from the electron if the it is a distance d away from the point charge, and what is the direction of that force? What is the weight of the point charge, and in what direction is that gravitational force on the point charge?

Doc Al said:
Better write that as:
$$F_e = \frac{k q_1 q_2}{d^2}$$

That's q_1. The other charge will be the electron. What's the charge and mass of an electron? (Look it up!)

The charge of an electron is 1.6 *10^-19 C and I have the mass of it too what do I do it that?

Follow Tedjn's advice! Analyze the forces acting on the electron: its weight (which way does that act?); the electric force due to the other charge (which way does that act?). Where must the electron be placed (with respect to the first charge) so that its weight is balanced by the electric force?

What's the weight of the electron? Figure out the distance "d" such that the electric force on the electron equals its weight. Hint: Set it up an equation symbolically before plugging in numbers.

## 1. What is Coulomb's Law?

Coulomb's Law states that the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

## 2. How does Coulomb's Law apply to electron placement?

Coulomb's Law determines the force between two charged particles, such as electrons. This force affects the placement of electrons in an atom, as they are attracted to the positively charged nucleus and repelled by other electrons with the same charge.

## 3. What is the significance of electron placement in an atom?

The placement of electrons in an atom determines its chemical and physical properties. The number and arrangement of electrons in the outermost energy level (valence shell) determine an atom's reactivity and ability to form chemical bonds.

## 4. How does the distance between electrons and the nucleus affect electron placement?

The closer an electron is to the nucleus, the stronger the attraction due to Coulomb's Law. This results in higher energy levels being filled first, before electrons are placed in higher energy levels further from the nucleus.

## 5. Are there any exceptions to Coulomb's Law and electron placement?

While Coulomb's Law is generally accurate in predicting electron placement, there are some exceptions, such as the effects of quantum mechanics on the behavior of electrons in atoms. Additionally, in certain circumstances, electron-electron repulsion may become stronger than electron-nucleus attraction, resulting in deviations from the expected electron placement.

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