Answer:
1.72E11 atomCu
Explanation:
Assumption: A square intersection
Since the cross section wire is assumed to be a square intersection, the height and the width of the wire are the same (equal)
and height = h = 45nm
Convert 45nm to centimetres (cm), we have
45nm * 10^-9m * 100cm / (1nm * 1m)
= 4.5 * 10^-6cm
Length. = 1mm
Convert 1mm to centimetre (cm) as well, we have
1mm * 1m * 100cm/(1000mm * 1m)
= 0.1cm
Now, we'll calculate the volume of the wire.
Using
Volume = length * height * width ---_--_ width = height
So,
Volume = 0.1 * 4.5 * 10^-6 * 4.5 * 10^-6
Volume = 2.025E−12 cm³
Lastly, we'll calculate the numbers of copper atoms using the following steps
1. We'll begin with the volume of the wire
2. We'll use the density of copper as a conversion factor to convert cubic centimetres (cm³) of copper to grams of copper.
3. We'll use the molar mass of copper as a conversion factor to grams of copper to moles of copper.
4. We'll use the Avogadro's number as a conversion factor to convert moles of copper to atoms of copper.
So, we have
2.025E−12 cm³Cu * 8.96g/cm³ * 1molCu * 6.022E23atomCu / (1cm³Cu * 63.546gCu * 1 molCu)
= 1.72E11 atomCu