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 bonds than Xenon (Xe) because it has an unfilled outer shell.

Step-by-step solution

Identify Electron Configuration

To determine which element is more likely to form chemical bonds, first look at the electron configuration of each. Xenon ( ext{Xe}) is a noble gas with a complete outer electron shell. Sodium ( ext{Na}), in contrast, has one electron in its outer shell.

Understand Bonding Tendancy

Elements with incomplete outer shells tend to form bonds to achieve stability by gaining, losing, or sharing electrons. Sodium, which has one electron in its outer shell, tends to lose this electron to achieve a stable configuration.

Compare Stability

Xenon is chemically inert because its outer shell is full, making it stable and unlikely to form bonds under normal conditions. Sodium is more reactive as it seeks to lose one electron to achieve the stable electron configuration of the noble gas (Neon).

Conclusion

Sodium ( ext{Na}) is more likely to form chemical bonds than Xenon ( ext{Xe}). Noble gases like Xenon rarely form bonds because they have full valence shells, while elements like Sodium frequently engage in reactions to lose an electron and reach a stable state.

Key concepts

Electron Configuration

Electron configuration refers to how electrons are arranged around the nucleus of an atom. Each electron occupies specific energy levels known as electron shells, which are further divided into subshells. This configuration dictates how an element behaves chemically.

The configuration is determined by the number of electrons. For instance, sodium (Na) has 11 electrons arranged as follows: 2 in the first shell, 8 in the second, and 1 in the third. This single electron in the outermost shell is crucial since it makes sodium highly reactive.

• Elements with a few electrons in their outermost shells tend to seek stability.
• By following the 'octet rule,' most elements strive to have eight electrons in their outermost shell.
• Thus, sodium easily loses its lone outer electron, resulting in a stable electron configuration similar to neon.

In contrast, elements like xenon (Xe) have a full outer shell. Xenon has a configuration of 2, 8, 18, 18, and 8 electrons, making it stable and less inclined to react with other elements. Understanding how each shell is filled helps in predicting an element's reactivity.

Noble Gases

Noble gases are a group of elements that are exceptionally stable due to their complete electron configurations. These elements, found in Group 18 of the periodic table, include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).

These gases do not easily form chemical bonds because:

• Their valence shells are complete with eight electrons, aligning with the octet rule.
• They present minimal chemical reactivity and are noncombustible.
• This full valence shell configuration results in very low energy levels compared to other elements, meaning they don't need additional electrons for stability.

Although noble gases are traditionally considered nonreactive, under special conditions, compounds including xenon can form. However, under normal conditions, they seldom engage in chemical reactions, contributing significantly to their description as "noble."

Valence Electrons

Valence electrons are the outermost electrons of an atom and are key players in chemical bonding. These electrons decide how an atom will interact with others.
Elements in the same group of the periodic table typically have the same number of valence electrons, which explains their similar chemical behaviors.

• For example, sodium (Na), with its single valence electron, falls under Group 1 and is highly reactive.
• This solitary valence electron means it can easily lose it to attain a noble gas electron configuration.
• Conversely, elements like xenon (Xe) already have full outer shells, including eight valence electrons, achieving stability naturally.

Thus, sodium is more inclined to react than xenon, as sodium works toward achieving a stable electron configuration by losing its valence electron, while xenon maintains its stability due to its complete outer shell.