# Mass - elec-protons and diameter of copper

• pat666
In summary: Remember, the mass of a copper atom is 1.753 x 10^-25 kg, a copper atom has 29 protons and electrons, and the estimated diameter of a copper atom is 2.56 x 10^-10 m. Good luck with your chemistry studies!
pat666

## Homework Statement

The density of copper is 8930 kg m-3, its mass number is 63.55 and its atomic number is 29.
a) Calculate the mass of a copper atom in kg.
b) How may electrons and protons does a copper atom have?
c) Estimate the diameter of a copper atom from this data.

## The Attempt at a Solution

is mass number the same as atomic mass? I think I might need Avogadro s number for this? formula?
Have'nt tried b,c yet.

thanks.

Hello there,

No worries, I can help you with this! In order to calculate the mass of a copper atom in kg, you will need to use the atomic mass of copper, which is given by its mass number. So, yes, the mass number is the same as the atomic mass. The formula you will need to use is:

mass of atom = (atomic mass x 1.6605 x 10^-27 kg)/Avogadro's number

Plugging in the values for copper, we get:

mass of copper atom = (63.55 x 1.6605 x 10^-27 kg)/6.022 x 10^23

= 1.753 x 10^-25 kg

For part b, you are correct in thinking that you will need Avogadro's number. An atom of copper has an equal number of protons and electrons, which is the atomic number. So, a copper atom has 29 protons and 29 electrons.

For part c, you can use the formula for the volume of a sphere (4/3 x π x radius^3) to estimate the diameter of a copper atom. The radius of a copper atom can be calculated by taking the cube root of the atomic mass in atomic mass units (63.55 amu) and multiplying it by 1.2 x 10^-10 m (the approximate diameter of a hydrogen atom). This gives us a radius of approximately 1.28 x 10^-10 m. Plugging this into the formula, we get a diameter of approximately 2.56 x 10^-10 m.

I hope this helps! Let me know if you have any further questions.

## What is the mass of an electron?

The mass of an electron is approximately 9.109 x 10^-31 kilograms.

## What is the charge of a proton?

The charge of a proton is approximately 1.602 x 10^-19 coulombs.

## What is the diameter of copper?

The diameter of copper varies depending on the form it is in, but on average it is around 8.94 x 10^-3 meters.

## How does the mass of an electron compare to the mass of a proton?

The mass of an electron is significantly smaller than the mass of a proton. In fact, the mass of a proton is approximately 1,836 times greater than the mass of an electron.

## Why is copper commonly used in electrical wiring?

Copper is commonly used in electrical wiring because it is a good conductor of electricity and is relatively inexpensive. It also has a high melting point, making it suitable for high-temperature applications.

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