Question

(a) What are the electron configurations of the ground states of fluorine \((Z=9)\) and chlorine \((Z=17) ?\) (b) Why are these elements placed in the same column of the periodic table?

Short answer

Answer: Fluorine and chlorine have similar electron configurations with their highest-energy orbitals being of the "p" type, containing 5 electrons (F: [2p^5] and Cl: [3p^5]). They are in the same group (Group 17/Halogens) in the periodic table because they have the same number of valence electrons, which leads to similar chemical properties and reactivity.

Step-by-step solution

Find electron configurations for Fluorine (F) and Chlorine (Cl)

To find the electron configurations of Fluorine (Z=9) and Chlorine (Z=17), we need to determine the sequence of energy levels and orbitals that are filled with their electrons. We can use the Aufbau principle, which states that electrons fill orbitals from lowest to highest energy. The order of orbital filling is as follows: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, and so on. For Fluorine (Z=9), the electron filling order is: 1s^2, 2s^2, 2p^5 For Chlorine (Z=17), the electron filling order is: 1s^2, 2s^2, 2p^6, 3s^2, 3p^5

Understanding the periodic table placement

Fluorine (F) and Chlorine (Cl) are both from Group 17 (also known as Group 7A or Group VIIA) in the periodic table. They are called halogens. Elements in the same group have the same number of valence electrons. The valence electrons are the outermost electrons of an element that are involved in chemical bonding. In the case of halogens, each element has 7 valence electrons.

Explain the connection between electron configurations and periodic table placement

The reason why both fluorine (F) and chlorine (Cl) are in the same group in the periodic table is that they have the same valence electron configuration. Their highest-energy orbitals are of the “p” type and contain 5 electrons. For example, the valence electron configuration of fluorine is [2p^5] and that of chlorine is [3p^5]. Thus, they share similar chemical properties and reactivity due to their similar valence electron configurations.