Question

figure 2: a bohr model of a potassium atom.
which electron in a potassium atom is most likely to leave the atom? justify your answer using the model above.
analysis questions:

1. using attraction, briefly explain why the electron shells closest to the nucleus fill up first.

Explanation:

Electrons are negatively charged and the nucleus is positively charged. According to Coulomb's law, the force of attraction \(F = k\frac{q_1q_2}{r^2}\) (where \(k\) is a constant, \(q_1\) is the charge of the nucleus, \(q_2\) is the charge of the electron, and \(r\) is the distance between them). Electrons in shells closer to the nucleus (\(r\) is smaller) experience a stronger electrostatic attraction to the positively - charged nucleus. So, these shells fill up first as electrons are more strongly bound (in terms of electrostatic forces) to the nucleus when they are in closer shells.

Answer:

Electron shells closest to the nucleus fill up first because the electrostatic attraction between the negatively - charged electrons and the positively - charged nucleus is stronger for electrons in closer shells (due to the inverse - square relationship in Coulomb's law \(F = k\frac{q_1q_2}{r^2}\), where a smaller \(r\) gives a larger \(F\)).