Question

Consider the electron configurations of the noble gases. Which valence sublevels are completely filled for each noble gas?

Short answer

The completely filled valence sublevels for each noble gas are: Helium (He): 1s, Neon (Ne): 2s, 2p, Argon (Ar): 3s, 3p, Krypton (Kr): 4s, 3d, 4p, Xenon (Xe): 5s, 4d, 5p, and Radon (Rn): 6s, 4f, 5d, 6p.

Step-by-step solution

Understand Electron Configurations

The electron configurations for an element can be determined based on its position in the periodic table. The electrons fill up the energy levels in a specific order: 1s, 2s, 2p, 3s, 3p, and so on. Each s sublevel can hold up to 2 electrons and each p sublevel can hold up to 6 electrons. The electron configuration can be written as the energy level followed by the sublevel and the number of electrons in that sublevel in superscript.

Identify Valence Electrons for Noble Gases

Noble gases are found in Group 18 (or 8A, in older notation) of the periodic table. They all have their outermost s and p sublevels completely filled. Since these are the highest energy levels, the electrons in these sublevels are the valence electrons. For example, helium (He) has 2 electrons in the 1s sublevel, neon (Ne) has 2 electrons in the 2s and 6 in the 2p sublevel, and argon (Ar) has 2 electrons in the 3s and 6 in the 3p sublevel.

List the Completely Filled Valence Sublevels for Each Noble Gas

The completely filled valence sublevels for each noble gas are: - Helium (He): 1s - Neon (Ne): 2s, 2p - Argon (Ar): 3s, 3p - Krypton (Kr): 4s, 3d, 4p - Xenon (Xe): 5s, 4d, 5p - Radon (Rn): 6s, 4f, 5d, 6p

Key concepts

Electron Configuration

Electron configuration is a way to represent the arrangement of electrons in the orbitals of an atom. It plays a crucial role in determining how an element will chemically interact with other elements. Electrons arrange themselves around the nucleus of an atom in specific energy levels and sublevels. These are filled in a defined sequence based on increasing energy, known as the Aufbau principle.

In order, the sublevels fill as follows: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, and so on. Each s sublevel can accommodate 2 electrons, while p sublevels can hold up to 6 electrons. This filling order helps explain the stability of noble gases as they have completely filled s and p valence subshells.

• 1s Sublevel: Holds 2 electrons.
• 2s and 2p Sublevels: Hold a combined total of 8 electrons.
• 3s and 3p Sublevels: Similarly hold a combined 8 electrons, further showing the pattern in electron configurations.

Valence Electrons

Valence electrons are the electrons located in the outermost shell of an atom. They are essential because they determine how an atom will bond with other atoms, forming molecules and compounds. For noble gases, these valence electrons completely fill their outer most s and p sublevels, rendering them highly stable and largely inert.

Noble gases, positioned in Group 18 of the periodic table, possess a full set of valence electrons. Here are examples:

• Helium (He): Has 2 electrons in its 1s sublevel.
• Neon (Ne): Completes its valence shell with 2 electrons in 2s and 6 electrons in 2p sublevels.
• Argon (Ar): Fills its valence with 2 electrons in 3s and 6 in 3p sublevels.

These complete configurations explain why noble gases do not usually form bonds under normal conditions.

Periodic Table

The periodic table is a critical tool in chemistry, organizing all known elements in a way that displays patterns and groups according to their properties and atomic structure. Elements are arranged in periods (rows) and groups (columns), which tell us about the electron distribution amongst their shells.

For instance, all elements in a given group, such as Group 18— the noble gases—share the property of having completely filled valence shells. This is reflected in their electron configuration and contributes to the periodicity of their chemical behavior. The noble gases are grouped together because of their unique, nonreactive nature, driven by a happy quartet of fully populated outer s and p subshells.

Energy Levels

Energy levels are designated regions around the nucleus of an atom where electrons are likely to be found. They are synonymous with electron shells. These levels get filled by electrons from lower energy to higher energy according to the Aufbau principle.

Each energy level can contain several sublevels, such as the s or p sublevels, that have specific shapes and capacities:

• s Sublevel: Holds up to 2 electrons.
• p Sublevel: Consists of 3 orbitals, each capable of holding 2 electrons (total of 6 electrons).

As electrons occupy these energy levels, they move to higher levels as needed, but the noble gases are unique because their outermost s and p sublevels are completely filled. This full occupancy contributes to their lack of chemical reactivity, making them stand out on the periodic table.