Question

The electronic configurations of four elements are given below: (1) \(\mathrm{ls}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{5}\) (2) \(1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{4}\) (3) \(1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{3}\) (4) \(1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{6} 3 \mathrm{~s}^{2} 3 \mathrm{p}^{4}\) Which of the following arrangements gives the correct order in terms of increasing electronegativity of the elements? (a) \(3<2<4<1\) (b) \(2>3>1>4\) (c) \(4<3<2<1\) (d) \(1<2<3<4\)

Short answer

Option (c) \(4 < 3 < 2 < 1\) is correct.

Step-by-step solution

Identify the Elements

First, match the electronic configurations to the corresponding elements using the Periodic Table. These configurations describe elements in their ground state: (1) \(\mathrm{ls}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{5}\) is Fluorine (F) (2) \(1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{4}\) is Oxygen (O) (3) \(1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{3}\) is Nitrogen (N) (4) \(1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{6} 3 \mathrm{~s}^{2} 3 \mathrm{p}^{4}\) is Sulfur (S).

Understand Electronegativity

Electronegativity is the tendency of an atom to attract a bonding pair of electrons. Generally, it increases across a period from left to right and decreases down a group. Thus, the order of electronegativity among the identified elements, based on their position in the Periodic Table, would be expected to be: \(\text{F} > \text{O} > \text{N} > \text{S}\).

Arrange Elements by Electronegativity

Convert the elements into their respective numbers as per their arrangements in the exercise choices: - Since F is most electronegative, and correlates to (1), in increasing order need to put F last.- O with (2), N with (3), and S with (4) will follow based on their decreasing electronegativity. - Therefore, the correct increasing order is \(4 < 3 < 2 < 1\).

Confirm the Correct Answer Choice

Compare the calculated order, \(4 < 3 < 2 < 1\), with the choices given: - (c) \(4 < 3 < 2 < 1\) matches our calculated order, so it is the correct choice.

Key concepts

Electronic Configuration

Electronic configuration is a way to describe the distribution of electrons in an atom. It is typically represented using numbers and letters that signify different energy levels and subshells. For instance, in the configuration \(1s^2 2s^2 2p^5\), the numbers represent the energy level, the letters denote the type of atomic orbital, and the superscripts show the number of electrons in those orbitals.

Understanding the electronic configuration helps us predict an element’s chemical properties. Electrons are arranged in shells around the nucleus, and the configuration not only tells us the number of electrons but also their energy levels. This arrangement is crucial for understanding how elements interact with each other in chemical reactions.

• Energy Levels: Higher numbers indicate higher energy levels farther from the nucleus.
• Subshells: Different letters (s, p, d, f) describe the shape of the orbitals.
• Electron Count: The superscripts help identify the number of electrons in each subshell.

Grasping this concept is essential for diving into the intricacies of chemical bonding and reactivity.

Periodic Table

The Periodic Table is a tabular arrangement of elements ordered by their atomic number, electron configuration, and recurring chemical properties. It serves not only as a reference for looking up elemental properties but also as a tool for educating about trends in chemical behavior.

The elements are organized into periods (horizontal rows) and groups (vertical columns) in a way that elements with similar properties reside in the same column. For example, in the original exercise, identifying elements based on their electronic configuration relied heavily on the Periodic Table. Knowing that fluorine's configuration \(1s^2 2s^2 2p^5\) corresponds with its position in the table helps in identifying its attributes like electronegativity.

• Groups: Elements in the same group have the same number of electrons in their outermost shell, which leads to similar chemical properties.
• Periods: Each period corresponds to the filling of a different electron shell.
• Metal, Nonmetals, and Metalloids: Classification helps predict electrical conductivity and general behavior.

Mastering the layout and use of the periodic table can enhance understanding of elemental chemistry and predict how an element might react.

Element Identification

Element identification through electronic configuration is a fundamental skill in chemistry, allowing you to determine the specific element based on how electrons are arranged. Each element has a unique configuration due to its distinct number of electrons.

By using the electronic configuration, for example, \(1s^2 2s^2 2p^6 3s^2 3p^4\) might be challenging without practice, but it directly points to sulfur (S) on the periodic table.

• Unique Configurations: Each element has a unique set of electrons which determine its chemical behavior.
• Link to Periodic Table: Use the periodic table to match configurations to elements.
• Prediction of Properties: Knowing the element permits prediction of its physical and chemical properties.

This understanding plays a big role in anticipating chemical reactivity and forming compounds.

Chemical Bonding

Chemical bonding is the process by which atoms combine to form compounds, and it's strongly influenced by the electronic configuration of the participating elements. Atoms tend to form bonds to achieve a stable electric configuration, often resembling that of noble gases.

There are primarily three types of bonds you should be aware of: ionic, covalent, and metallic. Electronegativity plays a critical role in bond formation; atoms with high electronegativity are more likely to attract electrons and form covalent bonds, as seen with fluorine in the exercise.

• Ionic Bonds: Form when electrons are transferred from one atom to another, usually involving a metal and nonmetal.
• Covalent Bonds: Form when atoms share electron pairs, usually between nonmetals.
• Metallic Bonds: Involve free-flowing electrons, providing metals their conductive properties.

Understanding chemical bonding is key to grasping how elements interact in molecular and lattice structures, making it crucial for higher-level chemistry studies.