A system consists of 55 electrons and 43 protons. (a) Is the total charge of the system positive or negative? Explain. (b) What is the total charge of the system?

A system consists of electrons and protons only. It contains 320 protons and has a total charge of-$51 e$. What is the mass of the system?

A system consists of electrons, protons, and neutrons. It contains 250 neutrons and 150 protons. If the total charge of the system is $-35 e$, what is its mass?

If a charge of0.30 C passes through a person's chest in 1.0 s, the heart can go into ventricular fibrillation-a nonrhythmic "fluttering" of theventricles that results in little or no blood being pumped to the body. If this rate of charge transfer persists for 4.5 s, how many electrons pass through the chest?

Two small spheres spaced 20.0 cm apart have equal charge. How many excess electrons must be present on each sphere if the magnitude of the force of repulsion between them is $3.33 \times 10 ^ { - 21 } \mathrm { N }$?

Find the total charge of a system consisting of $3.9 \times 10^{7}$ electrons.