Step-by-step explanation:
We have a nickel coin and its mass is 4.99 grams. With the molar mass we can find the number of moles of Ni that we have in the coin.
mass of Ni coin = 4.99 g
molar mass of Ni = 58.7 g/mol
moles of Ni = mass of Ni/molar mass of Ni
moles of Ni = 4.99 g/(58.7 g/mol)
moles of Ni = 0.0850 mol
So, the coin has 0.0850 moles of Ni. We know that 1 mol of Ni contains 6.02 * 10^23 atoms. We can find the number of atoms of Ni that we have in the coin.
1 mol of Ni = 6.02 *10^23 atoms of Ni
atoms of Ni = 0.0850 mol * 6.02*10^23 atoms of Ni/(1 mol)
atoms of Ni = 5.12 *10^22 atoms
We found that 1 nickel coin has 5.12 *10^22 atoms of Ni. The atomic number of Ni means that one atom of Ni has 28 protons. Since the charge of the Ni atom is zero, the Ni atoms also has 28 electrons.
atomic number of Ni = 28 = n° of protons = n° of electrons
number of electrons = 5.12 *10^22 * 28 electrons/atom
number of electrons = 1.43 * 10^24 electrons
The coin has 1.43 *10^24 electrons. The charge of one electron is 1.6 *10^(-19) Coulombs. Finally, we can find the charge of electrons in a Ni coin.
1 electron = 1.6 *10^(-19) Coulombs
charge of electrons = 1.43 *10^24 electrons * 1.6 *10^(-19) Coulombs/electron
charge of electrons = 2.29 *10^5 coulombs
Answer: The charge on the electrons in a nickel coin is 2.29 * 10^5 coulombs.