A 45.0 g ball of copper has a net charge of 1.5 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.)

To determine the fraction of electrons that have been removed from the copper ball, we need to calculate the total number of electrons in the ball and then compare it to the number of electrons necessary for a neutral copper ball.

Here's how you can do it:

Step 1: Calculate the number of copper atoms in the ball.
To do this, divide the mass of the copper ball by the atomic mass of copper:
Number of copper atoms = Mass of copper ball / Atomic mass of copper

Mass of copper ball = 45.0 g (given)
Atomic mass of copper = 63.5 g/mol (given)
Number of copper atoms = 45.0 g / 63.5 g/mol

Step 2: Calculate the number of electrons in the ball.
Since each copper atom has 29 protons and is neutral, it also has 29 electrons.
Number of electrons in the ball = Number of copper atoms × 29 electrons

Step 3: Determine the net charge on the copper ball.
The net charge on the copper ball is given as 1.5 µC (microcoulombs).
We know that 1 coulomb (C) is equal to 6.24 × 10^18 electrons.
Therefore, 1.5 µC is equal to 1.5 × 10^-6 C.
Net charge on the copper ball = 1.5 × 10^-6 C

Step 4: Calculate the number of electrons necessary for a neutral copper ball.
Since the net charge on the copper ball is positive, electrons have been removed.
We can find the number of removed electrons by converting the net charge to the number of electrons using the conversion factor mentioned earlier.
Number of removed electrons = Net charge on the copper ball × (6.24 × 10^18 electrons/Coulomb)

Step 5: Calculate the fraction of electrons removed.
To calculate the fraction of electrons removed, divide the number of removed electrons by the total number of electrons in the ball.
Fraction of electrons removed = Number of removed electrons / Number of electrons in the ball

Now you can go ahead and plug in the numbers to find the answer!