# What is the Fraction of Electrons Removed from a Charged Ball of Copper?

• tuggler
In summary, the conversation discusses a question regarding the fraction of electrons removed from a 48.7 g ball of copper with a net charge of 2.2 µC. The solution involves calculating the number of electrons normally present in the copper, determining the number of electrons removed, and finding the fraction removed. However, the initial calculation for the number of electrons normally present was incorrect, resulting in an incorrect answer. After correcting the mistake, the correct answer was obtained.
tuggler

## Homework Statement

A 48.7 g ball of copper has a net charge of 2.2 µC. What fraction of the copper's electrons have been removed? (Each copper atom has 29 protons, and copper has an atomic mass of 63.5.).

## The Attempt at a Solution

Number of electrons normally present ..
(48.7/63.5)mol x 6.022^23(atoms per mol) x 29(electrons per atom) = 1.34^24 electrons

Electrons removed = n
ne = 2.20^-6C .. .. n = 2.20^-6C / 1.60^-19C/e .. .. n = 1.38^13 electrons removed

Fraction removed = 1.38^13 removed / 1.34^24 total

But the answer is wrong. I don't know what I am doing wrong?

tuggler said:
Number of electrons normally present ..
(48.7/63.5)mol x 6.022^23(atoms per mol) x 29(electrons per atom) = 1.34^24 electrons

Check the result. 6.022*10^23 (note the correct notation) times 29 should be pretty close to 180*10^23 ≈ 2*10^25, and 48.7/63.5 is close to 1, so you should be in the 10^25 ballpark, not 10^24.

Yup, you're correct! Thanks. Sometimes it's really hard catching your own mistake. Thanks again!

## What does "Fraction of electrons removed" refer to?

"Fraction of electrons removed" refers to the percentage or ratio of electrons that have been taken out of a material or substance.

## How is the fraction of electrons removed calculated?

The fraction of electrons removed is calculated by dividing the number of electrons that have been removed from a material by the total number of electrons in that material.

## Why is the fraction of electrons removed important in scientific research?

The fraction of electrons removed is important in scientific research because it can provide information about the properties and behavior of the material. It can also help in understanding chemical reactions and electrical conductivity of substances.

## What factors can affect the fraction of electrons removed?

The fraction of electrons removed can be affected by various factors such as the type of material, temperature, pressure, and the presence of other substances or impurities.

## How can the fraction of electrons removed be measured?

The fraction of electrons removed can be measured through various methods such as spectroscopy, electrochemistry, and Hall effect measurements. These methods involve analyzing the behavior of electrons in a material and determining the changes in their concentration.

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