Electric Charge Practice Problems

Two tiny iron balls to be used in an electrostatics experiment have a mass of 0.0550 kg each. The balls are placed 65.0 cm apart. Determine the number of electrons on each neutral ball. (Iron has an atomic mass of 55.85 g/mol and atomic number 26)

Determine the mass of Silver (atomic number 47) having a total nuclear charge of 3.5 C.

If you have a container with 3.0 litres of water at room temperature and atmospheric pressure; what would be the total electrical charge of electrons in water?[Molar mass of water is 18.015 g/mol.]

Two protons are released from rest at a separation distance of approximately one atomic diameter, equal to 1.0 × 10^-10 m, from each other in vacuum space. Find the magnitude of their initial acceleration. [Hint: A proton has mass m_p = 1.67 × 10^-27 kg, charge = 1.60×10^-19 C, and The Coulomb's constant k = 8.99 × 10⁹ N⋅m²/C².]

Imagine that you are studying a massive block of pure iron that weighs around 5 kilograms. You are aiming to calculate the total negative charge of all electrons found inside of this block. Additionally, you need to determine the overall electrical neutrality of this particular block. Note that Iron has a atomic weight of approximately 56 atomic mass units per mole, and contains 26 electrons per atom. 

Consider a scenario involving two ion pairs: NaCl and MgF. The charges of the ions are as follows: Na⁺ and Cl⁻ have charges +1.00𝑒 and -1.00𝑒, respectively. On the other hand, Mg²⁺ and F⁻ have charges +2.00𝑒 and -1.00𝑒, respectively, where 𝑒=1.602×10⁻¹⁹ C. Calculate the net electrostatic force between the NaCl ion pair and the MgF ion pair, considering the positive direction to be to the right. Hint: Ignore the forces between ions of the same pair.

Consider a setup where 76 cm-long wires terminate in 25-gram spheres positioned at a 30-degree angle from the vertical axis. These spheres accumulate charge when the setup is charged. Calculate the total charge Q imparted to this system. Assume the influence of the wire mass to be negligible in your calculations.

A chemist is studying a sample of liquid ethanol (C₂H₅OH) which has a molecular mass of 46 u. If the chemist has a 1.4 liter sample of this ethanol, how many protons are present within this volume?

A student rubs a rubber balloon against her hair. In turn, the charge gained by the balloon is -1.2 microcoulomb. How many electrons are transferred from the student's hair to the balloon?

Two identical metal balls are initially uncharged and separated by a distance of half a meter apart in a vacuum. A certain number of electrons is transferred from one ball to another, resulting in an attractive force of magnitude equal to 0.025 Newtons. How many electrons were removed from one ball and added to another?

Determine the number of electrons on the sphere carrying a charge of -62.0 μC.

A small charge with a mass "m" of 2.0 grams is attached to an insulating string that is 60 cm long. This setup is observed to be in equilibrium within a uniform horizontal electric field of 9600 N/C. The electric field direction is to the right as shown in the figure below. Calculate the magnitude and sign of the point charge when the pendulum's position, as shown in a corresponding figure, is 14 cm above its lowest vertical position.