# What is the n value for Li2+ ion in the Bohr model of the atom?

• physicsnobrain
In summary: It is +3. So there is no need to use the equation for this problem? Seems more challenging than that.
physicsnobrain

## Homework Statement

In the equation for the bohr model of the atom, what is the n value for Li2+ ion?

## Homework Equations

E = -2.178 x 10^-18J(z^2/n^2)

## The Attempt at a Solution

Since it is Li2+ that means it has 1 electron. So z = 1. Now I have an equation with 2 variables (impossible to solve).

I don't know what E is and I have to find n. Does anyone have any idea on how to do this?

z is the charge of the nucleus and is not 1 for Li.
For the rest, it may help to post the complete text of the problem.

nasu said:
z is the charge of the nucleus and is not 1 for Li.
For the rest, it may help to post the complete text of the problem.

It's Li2+ not Li. And this is the complete text of the problem...

It does not matter. The charge of the nucleus is 3e for Li, Li+, Li2+.
So z=3.

But n can take any value so the question does not seem to make sense.

IF the question is instead: In the equation for the bohr model of the atom, what is the z value for Li2+ ion?

Does this make more sense?

physicsnobrain said:
IF the question is instead: In the equation for the bohr model of the atom, what is the z value for Li2+ ion?

Does this make more sense?
Yes.

DrClaude said:
Yes.

Well isn't there still three unknown variables Energy and n value and z value?

But you are not asked to find all three, just to tell what (most likely) Z is.

As worded question doesn't make sense, unless it asks for Z, not n.

physicsnobrain said:
Well isn't there still three unknown variables Energy and n value and z value?

What is Z? What does it mean? What is Z for lithium?
(yay! 200th post)

The question exactly as it appears word for word is: In the equation for the Bohr model of the atom, what is the Z value for Li2+ ion?

physicsnobrain said:
The question exactly as it appears word for word is: In the equation for the Bohr model of the atom, what is the Z value for Li2+ ion?

You had the right equation in the OP. Go back in your notes/textbook and find what the ##Z## stands for.

DrClaude said:
You had the right equation in the OP. Go back in your notes/textbook and find what the ##Z## stands for.

it stands for nuclear charge.

And what is nuclear charge for lithium?

Borek said:
And what is nuclear charge for lithium?

It is +3. So there is no need to use the equation for this problem? Seems more challenging than that.

No, it is as simple as that. You were making it more difficult than it is from the very beginning.

## What is the difference between a physical change and a chemical change?

A physical change is a change in the physical properties of a substance, such as shape, size, or state of matter, without altering its chemical composition. A chemical change, on the other hand, results in the formation of a new substance with different chemical properties.

## What is the difference between an atom and a molecule?

An atom is the smallest unit of matter that retains the chemical properties of an element. It is made up of a nucleus containing protons and neutrons, surrounded by electrons. A molecule, on the other hand, is a group of two or more atoms held together by chemical bonds.

## What is the difference between potential energy and kinetic energy?

Potential energy is the energy an object possesses due to its position or state, such as gravitational potential energy or chemical potential energy. Kinetic energy, on the other hand, is the energy an object possesses due to its motion. It is calculated as 1/2 times the mass of an object times its velocity squared.

## What is the difference between heat and temperature?

Heat is the transfer of thermal energy from one object to another due to a difference in temperature. Temperature, on the other hand, is a measure of the average kinetic energy of the particles in a substance. It is measured in degrees Fahrenheit, Celsius, or Kelvin.

## What is the difference between a conductor and an insulator?

A conductor is a material that allows electricity or heat to flow through it easily. Metals are good conductors due to the presence of free electrons. An insulator, on the other hand, is a material that does not allow electricity or heat to flow through it easily. Examples include rubber, plastic, and glass.

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