Question

Which of the following elements is more likely to form chemical bonds: xenon (Xe) or sodium (Na)? Explain why.

Short answer

Sodium (Na) is more likely to form chemical bonds because it is a reactive alkali metal with one valence electron to lose.

Step-by-step solution

Understand Periodic Table Position

Xenon (Xe) is a noble gas located in Group 18 of the periodic table. Noble gases are known for having full valence electron shells, which makes them very stable and generally unreactive. Sodium (Na) is an alkali metal found in Group 1. Alkali metals have one electron in their outermost shell, which they tend to lose easily in order to achieve a stable electron configuration.

Consider Electron Configuration

Xenon has a complete octet in its valence shell (8 electrons), following the oble gas configuration \( [Kr] 4d^{10} 5s^{2} 5p^{6} \). Since its electron arrangement is stable, xenon does not usually form bonds. Sodium, on the other hand, has the electron configuration \( [Ne] 3s^{1} \). With only one valence electron, it is unstable and eager to lose that electron to achieve the stable configuration of a noble gas (neon).

Evaluate the Reactivity

Noble gases like xenon are mostly inert due to their full valence shell, which means they have little tendency to react with other elements. However, alkali metals such as sodium are highly reactive. Sodium will readily lose its single valence electron to form positive ions (Na⁺) and achieve a more stable electronic configuration.

Determine Likely Element to Form Bonds

Sodium, with its single valence electron, is highly prone to form chemical bonds, particularly ionic bonds, by losing that electron to achieve stability. Xenon, on the other hand, is not inclined to form chemical bonds under normal conditions due to its stable electron configuration.

Key concepts

Periodic Table

The periodic table is a chart that organizes elements based on their atomic number, electron configurations, and recurring chemical properties. Each column is known as a "group" and elements within the same group have similar characteristics. Understanding the periodic table helps predict how elements may behave in a chemical reaction.

• Groups: Vertical columns where elements share similar properties.
• Periods: Horizontal rows that indicate the number of electron shells.
• Trends: As you move across a period, elements become less metallic and more non-metallic; moving down a group, elements become more metallic.

Elements in Group 18 are noble gases, known for their stability. Group 1 includes alkali metals, which are highly reactive. This organization provides crucial insights into the reactivity and bonding tendencies of elements.

Electron Configuration

Electron configuration refers to the arrangement of electrons in an atom's electron shells. It's a key concept in understanding why certain elements react the way they do. Here's how it's structured:

• Energy Levels: Electrons exist in layers or shells around the nucleus, denoted by numbers (1, 2, 3, etc.).
• Subshells: Within each energy level, subshells are represented by letters (s, p, d, f).
• Filling Order: Electrons fill the lowest available energy levels first (the Aufbau principle).

For example, xenon has the electron configuration \[ [Kr] 4d^{10} 5s^{2} 5p^{6} \], representing a full valence shell. Sodium, with \[ [Ne] 3s^{1} \], has just one electron in its outer shell, making it more reactive as it seeks to lose that electron to achieve a stable configuration like its nearest noble gas.

Noble Gases

Noble gases are a group of elements in Group 18 of the periodic table. These elements, including xenon, feature completely filled valence electron shells, giving them exceptional chemical stability. As a result, they don't usually form bonds.

• Characteristics: Noble gases are colorless, odorless, and tasteless, with very low chemical reactivity.
• Full Valence Shells: They have a complete octet (8 electrons) in their outer shell, with helium as an exception having 2 electrons.
• Inert Behavior: Due to their stability, noble gases have little tendency to gain or lose electrons.

Under usual conditions, noble gases are nonreactive. However, under specific high-energy conditions, heavier noble gases like xenon can form compounds, although these occurrences are rare.

Alkali Metals

Alkali metals, found in Group 1 of the periodic table, are highly reactive elements. They have a single electron in their outermost shell, making them eager to participate in chemical reactions by losing that electron. Sodium is a classic example of an alkali metal.

• Reactivity: Alkali metals easily lose their lone valence electron to form positive ions (cations).
• Soft and Silvery: These metals are typically soft and have a shiny, metallic luster.
• Low Density: Most are less dense than water, with lithium, sodium, and potassium being able to float.

Because of their reactivity, alkali metals are not found in nature in their elemental form. They quickly react, often violently, with water and other substances to form more stable compounds.