General Chemistry

Gold, with the chemical symbol Au and atomic number 79, is a highly sought-after precious metal known for its lustrous yellow color and wide range of applications, from jewelry to electronics. The atomic number of an element indicates the number of protons in its nucleus, and for a neutral atom, this is also equal to the number of electrons. Therefore, a gold atom has 79 electrons. The electronic structure of an atom describes the distribution of its electrons in different energy levels or shells around the nucleus. These energy levels are further divided into sublevels, which are designated as s, p, d, and f. The arrangement of electrons in these sublevels is governed by a set of principles: the Aufbau principle, the Pauli exclusion principle, and Hund's rule. The electronic configuration of gold can be determined using the Aufbau principle, which states that electrons fill orbitals starting from the lowest energy level to higher energy levels. Gold's electronic configuration can be written as follows: $$ \text{Au: } [Xe]4f^{14}5d^{10}6s^1 $$ Here, [Xe] represents the electron configuration of xenon, a noble gas with 54 electrons, which serves as a shorthand for the filled energy levels that gold shares with xenon. The remaining electrons fill the 4f, 5d, and 6s orbitals. The electronic configuration of gold reveals that it has a completely filled 4f sublevel, a completely filled 5d sublevel, and a single electron in the 6s sublevel. This configuration is significant for several reasons: 1. **Conductivity**: The presence of a single electron in the 6s orbital makes gold an excellent conductor of electricity. Electrons in the outermost shell can move freely, which is a key characteristic of good conductors. 2. **Malleability and Ductility**: The completely filled d sublevel contributes to gold's malleability and ductility. The d electrons can delocalize and form metallic bonds, which are non-directional in nature. This allows gold atoms to slide past each other under stress without breaking bonds, making gold easy to shape and stretch. 3. **Color**: The relativistic effects, which become significant in heavier elements like gold, cause a contraction and energy level splitting in the 6s orbital. This leads to absorption of light in the blue region of the spectrum, giving gold its characteristic yellow color as it reflects the red and yellow light. 4. **Inertness**: Gold is known for its chemical inertness, meaning it does not react easily with other substances. This is due to the stability of its filled 5d sublevel, which makes it less likely to form bonds with other atoms. As a result, gold is resistant to corrosion and tarnishing. 5. **Catalytic Properties**: Although gold is inert, it can act as a catalyst when divided into small particles, as the surface atoms can participate in chemical reactions. The 5d electrons play a role in these catalytic processes. In summary, gold has 79 electrons, and its electronic structure, particularly the filled 4f and 5d sublevels along with a single 6s electron, contributes to its high conductivity, malleability, ductility, characteristic color, chemical inertness, and potential catalytic activity. These properties make gold a valuable material in various industries and applications.

Question

How many electrons does gold have, and how does its electronic structure influence its chemical and ...

Solution

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