There are 7.86 x 10²³ electrons in a 30.0 cm length of 12-gauge copper wire with a diameter of 2.05 mm.
To calculate the number of electrons in a 30.0 cm length of 12-gauge copper wire (diameter 2.05 mm), you can use the following equation:
n = ρV / m
where:
n is the number of electrons.ρ is the density of copper (8.96 g/cm³).V is the volume of the wire. m is the mass of one copper atom.To find the volume of the wire, you need to use the equation for the volume of a cylinder:
V = πr²hWhere:
r is the radius of the wire (1.025 mm). h is the length of the wire (30.0 cm).Therefore, V = π(1.025 mm)²(30.0 cm) = 9.30 cm³The mass of one copper atom is 63.55 g/mol or 1.054 x 10⁻²² g. To find m, you need to use Avogadro's number (6.02 x 10^23 atoms/mol):m = (63.55 g/mol) / (6.02 x 10^23 atoms/mol) = 1.055 x 10⁻²² g
Now, you can plug in the values:
n = (8.96 g/cm³)(9.30 cm³) / (1.055 x 10⁻²² g) = 7.86 x 10²³ electrons
Therefore, there are 7.86 x 10²³ electrons in a 30.0 cm length of 12-gauge copper wire with a diameter of 2.05 mm. This should be rounded to 2 significant figures, so the final answer is 7.9 x 10²³ electrons.
Learn more about electrons: https://brainly.com/question/26084288
#SPJ11