Each atom in a 7.0 microgram piece of calcium (A=40, Z=20) has one electron removed. What is the magnitude of the total charge collected in this way?
A) 34 mC
B) 670 mC
C) 17 mC
D) 60 mC

Question

Quizplus · Accepted Answer

The total number of calcium atoms in the sample can be calculated using the given mass and the molar mass of calcium:

Number of atoms = (7.0 micrograms) / (40 g/mol) x (1 mol / 6.022 x 10^23 atoms) = 2.92 x 10^16 atoms

Each of these atoms has one electron removed, resulting in a +1 charge. Therefore, the total charge collected is:

Total charge = (number of atoms) x (charge per atom) = (2.92 x 10^16 atoms) x (1.6 x 10^-19 C/atom) = 4.67 mC

This is closest to answer choice C, 17 mC. The other choices are much larger than the calculated value and can be easily eliminated.

Each Atom in a 7