Question

How many shells are occupied by electrons in a gold atom, Au (atomic number 79)?

Short answer

Gold has electrons in 6 shells.

Step-by-step solution

Understand the Atomic Structure of Gold

Gold (Au) has an atomic number of 79, which means it has 79 electrons in a neutral atom. These electrons are distributed across various energy shells or levels.

Determine Electron Configuration Blocks

Electrons are filled into different blocks based on the periodic table: the s, p, d, and f blocks. Gold's electron configuration ends in the d block, specifically the 5d block.

Write the Electron Configuration

Write down the full electron configuration for gold. Gold's electron configuration is: \[ 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6 \, 3d^{10} \, 4s^2 \, 4p^6 \, 4d^{10} \, 5s^2 \, 5p^6 \, 4f^{14} \, 5d^{10} \, 6s^1 \]

Identify the Occupied Shells

Electrons are located in different principal quantum levels, or shells, denoted by the principal quantum number \( n \). For gold, the populated shells can be identified from its electron configuration as: \( n=1 \), \( n=2 \), \( n=3 \), \( n=4 \), \( n=5 \), and \( n=6 \).

Key concepts

Atomic Structure

The concept of atomic structure forms the foundation of understanding how elements like gold are built on a microscopic level. At the heart of an atom lies the nucleus, composed of protons and neutrons. Surrounding the nucleus are electrons, which are negatively charged particles. These electrons are not just randomly scattered but are organized in a structured manner around the nucleus.

• Each atom has a specific number of electrons equal to its atomic number. For gold, this number is 79.
• Electrons are arranged in levels or shells, symbolized by principal quantum numbers such as 1, 2, 3, etc.
• The distribution of electrons in these shells dictates the chemical properties of the element.

Knowing how electrons fill these levels is key to predicting how elements will interact in chemical reactions. This organization follows specific rules, a principle central to the periodic table's arrangement.

Gold Atom

Gold, symbolized as Au, is not just known for its radiance and value, but also for having a unique electron arrangement. This precious metal has an atomic number of 79, giving it 79 electrons in a neutral atom. Understanding the electron configuration helps us comprehend its stability and chemical behavior.

• Gold's electron configuration culminates in the 5d block of the periodic table, indicating significant d-orbital involvement.
• The configuration is given as: \[ 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6 \, 3d^{10} \, 4s^2 \, 4p^6 \, 4d^{10} \, 5s^2 \, 5p^6 \, 4f^{14} \, 5d^{10} \, 6s^1 \]
• This complex structure includes filled and partially filled orbitals, contributing to gold's excellent conductivity and resistance to tarnish.

The richness of gold's electron configuration plays a role in its distinct properties, making it a highly sought-after element both in nature and industry.

Energy Levels

Energy levels, also referred to as electron shells, are integral parts of an atom's architecture, defining where electrons reside relative to the nucleus. These levels are denoted by the principal quantum number \( n \), with each increase indicating a higher energy state.

• Electrons in lower energy levels have less energy and are closer to the nucleus.
• In the case of gold, electrons are distributed across six shells: \( n=1 \), \( n=2 \), \( n=3 \), \( n=4 \), \( n=5 \), and \( n=6 \).
• This layering is essential for understanding electron configuration and chemical bonding behavior.

Energy levels help predict how atoms will bond and react with each other. As you move away from the nucleus, electrons in higher energy levels have more energy and space to move, influencing how they participate in forming chemical bonds. Understanding these levels provides insights into the reactivity and intermolecular interactions of elements like gold.