Gold

Gold was known to the Greeks as Aurum, "a shining dawn."

The elemental symbol for Gold, Au, is a tribute to this shining dawn. Not to be confused with Ag (Greek: Argentum), which is the "shiny white" substance we know as Silver.

According to Investopedia, Gold has inherent value because "the metal is abundant enough to create coins but rare enough so that not everyone can produce them. Gold doesn't corrode, providing a sustainable store of value, and humans are physically and emotionally drawn to it."

Gold's position on the periodic table makes it a metal; many of its desirable features can be attributed to its metallic properties.

Gold has a lot of orbitals.

Au is a pretty big atom, with an atomic number of 79 and an atomic mass of 196.97. In its elemental state, it has 79 electrons. Elements typically "ionize" when they remove or gain outer orbital electrons to retain a full outer shell. Gold has 1 electron in it's outer shell, so it yeets it off ASAP. Au+1 is the most common ion for Gold. Compounds with gold ions are "aurous" or "auric".

Gold atoms interact in metallic bonds modeled by a "sea of electrons."

When multiple Gold atoms come together as a solid, they have enough space in their unoccupied electron orbitals to share extra electrons across multiple atoms. This is known as the "sea of electrons" model, and can help explain many of the attributes of metals like Gold, discussed below.

When an electron is excited by light, it goes up in energy. These levels of energy are quantified (n = 1, n =2, n = 3, etc) It releases this energy as another photon, which eventually hits our eyes and gives that substance it's unique color.

Gold has luster.

Because of the "sea of electrons" model, metals can absorb photons of many frequencies and also give off many frequencies of light. This causes many metals, like Gold, to have a valuable shine that we call "luster".

Gold is ductile.

Because of the "sea of electrons" model, metals can be drawn out into wires. This is known as ductility. Substances that don't share distributed electrons, like NaCl salt, fracture into crystals.

Gold is a good conductor of electricity.

Because of the "sea of electrons" model, metals allow electrons to flow across the substance. This free flow of electrons is known as "electricity." Expensive audio cables advertise good conductivity with gold-plated tips, which may provide a slightly better connection even though the increased cost is probably not warranted.

Gold is malleable.

Because of the "sea of electrons" model, metals can be pounded down into thin sheets but still retain a stable structure. Gold can be pounded down into very thin sheets, often called "gold leaf".

A lot of gold jewelry is actually other metals coated in layers of gold sheeting. Solid gold is more expensive than gold filled or gold plated pieces.

Gold was instrumental to the development of our current atomic model.

(1803) John Dalton

JD was the first scientist to introduce a concise atomic model. He worked with gas chemicals, and noticed that certain gasses would interact with some other gasses, but not with others. To help explain his observations, he claimed that all atoms of a particular element were similar to others of the same element. His model was basically that atoms exist as spheres.

Just a boring sphere.

John Dalton didn't make accurate recollections of the origin of his theory. The sphere was just here.

(1897) JJ Thompson

JJ Thompson shot cathode rays through a tube by heating a metal to release particles and passing those particles through an electric field. The Cathode Ray Tube (CRT) is still used in some old TVs to project a image on a screen.

JJ noticed that those particles would react with a magnet, which was a known property of electricity. He proposed that part of atoms must be charged, and developed the plum pudding model to describe the positive and negative charged pieces of an atom. These would later be named "electrons" by a colleague of JJ.

This model was proven incorrect by JJ's own student, Rutherford, but it still helped push scientific understanding to where it is now.

Tasty electron plums in a positively spread pudding. Also known as atomic fruitcake.

(1911) Rutherford & Hayes

R&H used thin gold foil and an alpha particle emitter to determine that the plum pudding model was incorrect, instead showing that the positive charge is isolated within a specific region in the middle of the atom. He reasoned that if the + charge was distributed evenly, like in the Thomson model, all alpha particles would pass through with similar trajectories. Instead, R&H saw a small amount of particles deflect back onto a screen. This indicated that a majority of the mass of the atom is centralized in a small volume in the center of the atom. We know that now as the nucleus.

Without R&H's gold foil experiment, we'd be in the dark on when it comes to the concept of an atomic nucleus.

(1913) Bohr

Bohr proposed that electrons do not just hover around a fixed nucleus indiscriminately, but are fixed in positions of quantum energy called orbitals.

The amount of electrons that each orbital can hold changes based on it's quantum numbers, which dictates it's energy level, it's shape, and it's orientation.

The Bohr model is the golden standard for Chemistry quizzes and diagrams. Try not to get to Bohr'd up in here.

The energy levels in the Bohr model are often compared to rungs on a ladder. High energy electrons aren't scared of heights.

(1926) Schrödinger

Also known for his fixation on the death of his cat, Schrödinger was never quite certain about anything in this world. He didn't think electrons were fixed in orbitals, but instead found in probabilistic electron clouds. If you know the energy level of an electron, you might be able to find it. Or you might not. Statistically.

You can't determine exactly where a propeller blade is, but you know it's average location based on the blur, sort of like the electron cloud.

(1964) Gell-Mann & Zweig

Physicists Murray Gell-Mann and George Zweig proposed a theory for "strong interaction symmetry" in particle physics. They proposed that important properties of protons and neutrons (the hadron particles) could be explained if they were made up of constituent particles. These "quarks" were just the beginning of elementary particle discoveries. New particles are currently being discovered that might help us solve the mysteries of the universe.

Some of these particles are strange. Literally.

CERN's Large Hadron Collider smashes particles together at massive speeds, creating opportunities for physicists to discover more particles. It might rip open a blackhole and devour our planet, but Geneva doesn't seem to mind.

VOD Tutorial 1 (Day 6)

VOD Tutorial 2 (Day 7)

Gold Original Content (15 points)

Gold as a material has been valuable through human history. But the ideas that come from that material are golden. Use this section to work on your atomic model building, so your understanding and editing skills are "rising dawn" level.

(3) Points: Google Slides Bohr model of Gold

(Smith) Bohr Model of Gold

You must create your Bohr model from scratch. Do not copy mine or use any from Google image search.

(4) Points: Google Slides atomic model of your name Elements

(Smith) Bohr Model of Name

(2) Points: Jewelry research

Take a picture of some of your prized personal jewelry. If you are not aware of the metallic composition of your jewelry, ASK a person who might know (parents) and post the information about that metal.

My wedding band is titanium carbide, brushed with rose gold.

"Titanium is a more resistant material, it doesn't rust and it weighs a lot less than gold in any of its variants. Titanium rings are difficult to scratch and bend out of shape, therefore perfect for those who are afraid of damaging their rings."
"No maintenance is necessary, unlike rings made of other materials."
"Titanium rings are more economical than those made with gold or silver." -Hitched (2021)

My wife's engagement ring is a rose-gold alloy, with a matching wedding band.

(6) points: Mystery Cable Detangle

People buy overpriced cables because they don't know any better. Gold plating is often used as an advertisement for expensive cables, but digital data delivery is often not sensitive enough to require more conductive gold contacts. A $1 HDMI cable will often produce the exact same result as the $130 cable.

Find at least 3 different cables at home. Take picture evidence of those cables and include a diagnostic analysis of that cable. Include info such as official name/version, year of design, what device it works with and how you acquired it.

Credit will not be given for re-using any of the following examples