Question

The outermost configuration of most electronegative element is: (a) \(\mathrm{ns}^{2} \mathrm{np}^{5}\) (b) \(\mathrm{ns}^{2} \mathrm{np}^{6}\) (c) \(\mathrm{ns}^{2} \mathrm{np}^{4}\) (d) \(n s^{2} n p^{6}\)

Short answer

(a) \( \mathrm{ns}^{2} \mathrm{np}^{5} \) is the outermost configuration of the most electronegative element, Fluorine.

Step-by-step solution

Understand Electronegativity

Electronegativity is the ability of an atom to attract electrons in a chemical bond. The most electronegative element is Fluorine.

Identify Electron Configuration

The electron configuration provides details of the arrangement of electrons around an atom. Specifically, the outermost configuration (valence electrons) determines reactivity and bonding. Fluorine, being in the 2nd period and group 17 of the periodic table, has the outermost electron configuration.

Determine Fluorine's Configuration

Fluorine has a total of 9 electrons. Its electron configuration is 1s² 2s² 2p⁵. Therefore, its outermost electron configuration is s^{2} p^{5}.

Match with Given Options

From the given options, we match Fluorine’s outermost configuration: (a) s^{2} p^{5} matches Fluorine’s configuration, confirming it is indeed option (a).

Key concepts

Electron configuration

Electron configuration is a notation that illustrates the distribution of electrons in an atom's orbitals. It follows the principles of quantum mechanics. Each electron shell, represented by "n," can hold a certain number of electrons, arranged in specific subshells such as s, p, d, and f.
Understanding electron configurations helps in predicting chemical properties and behaviors of elements. It follows some key rules:

• Pauli Exclusion Principle: No two electrons in a single atom can have identical quantum numbers.
• Aufbau Principle: Electrons fill orbitals starting from the lowest energy level.
• Hund’s Rule: Every orbital in a subshell is singly occupied before it can be doubly occupied.

The arrangement determines how an atom will react and what compounds it can form.

Valence electrons

Valence electrons are the outermost electrons of an atom and play a crucial role in chemical reactions. These are housed in the electron configuration’s last shell or energy level.

They are responsible for forming bonds with other atoms to create molecules and compounds. The number of valence electrons determines an element’s reactivity and bonding behavior.

• Elements in the same group: Have the same number of valence electrons, hence similar chemical properties.
• Determining Valence Electrons: For main group elements, it typically equals the group number.

Fluorine, with its outermost electron configuration of "2s² 2p⁵," has 7 valence electrons, making it highly reactive and electronegative.

Fluorine

Fluorine is a chemical element with the symbol F and atomic number 9. It belongs to the halogens group (Group 17) in the periodic table.

It is the most electronegative element, strongly attracting electrons from other atoms to complete its outer electron shell. This property makes Fluorine very reactive and a strong oxidizing agent.

• Electron Configuration: Fluorine's electron configuration is 1s² 2s² 2p⁵.
• Reactivity and Bonds: Due to its electronegativity and 7 valence electrons, Fluorine typically forms ionic or covalent bonds by gaining one electron.

These features make Fluorine a significant element in both industrial applications and biological systems.

Periodic table groups

The periodic table groups are the vertical columns on the periodic table containing elements with similar chemical behaviors. Each group shares the same number of valence electrons, guiding their reactivity and bonding.

• Group 1 - Alkali Metals: Highly reactive metals with 1 valence electron.
• Group 17 - Halogens: Very reactive nonmetals like Fluorine, which have 7 valence electrons.
• Group 18 - Noble Gases: Non-reactive gases with full electron shells.

The similarities in elements' properties within a group arise because they have similar valence electron configurations. This systematic arrangement allows prediction of elemental behavior and facilitates the study of chemical reactions.