Gold was the first metal that most people were familiar with since it was naturally occurring and could be found in riverbeds as yellow nuggets. Gold mining started in Egypt around 2,000 BCE. Alchemists attempted to transform other metals, such as copper or lead, into gold for millennia. Alchemists would have realized their efforts were in vain if they had grasped the atomic structure of gold and its chemical reactivity.
Chemical Properties of Gold
Group 11 of Period 6 of the periodic table contains gold as a transition metal. Although its sign, Au, comes from the Latin word for gold, aurum, its name is derived from the Old English word geolo, which means “yellow.”
Alchemists made several attempts, but their experiments were unsuccessful. Gold doesn’t respond too much. It will dissolve in aqua regia, a solution made of hydrochloric and nitric acids.
Historical note: To prevent their medals from being confiscated by the Nazi administration, a number of scientists who won the Nobel Prize dissolved them in aqua regia.
Understanding Atomic Structure: Fundamentals
A thorough grasp of atomic structure is required in order to comprehend the atomic structure of gold. Early in the 20th century, Danish physicist Niels Bohr provided a straightforward model for atom structure that could be used to see the atomic structure of gold. Historical note: During World War II, Niels Bohr concealed the dissolved gold and noble metals in his laboratory.
The positively charged core of an atom made up of protons and neutrons is known as the nucleus. The term “nucleon” refers to the combination of protons and neutrons. Electrons, the third major subatomic particle in an atom, are found outside the nucleus.
Identifying Protons and Neutrons in Atomic Structure
A proton is a positively charged subatomic particle with a mass of 1.67 x 10-24 grams or 1 atomic mass unit. An element is defined by the number of protons in its nucleus; helium, for instance, is an element with two protons. The element identity varies with the number of protons in the nucleus.
Atomic Structure of Gold: Nucleus
It is possible to see the number of atoms in gold with a rudimentary grasp of atomic structure.
Remember that an element’s identity is determined by its proton count. Gold’s nucleus has 79 protons. The atomic number, which is often seen above the element’s symbol on a periodic table, indicates how many protons are present in that element.
Find the element’s atomic mass (often found beneath the symbol) to determine the number of neutrons present. The mass of gold is equal to 197 atomic mass units. Deduct the mass of the atom from the number of protons. 197 – 79 = 118 for gold. Neutrons make up gold’s 118.
Therefore, there are 79 protons and 118 neutrons in the nucleus of gold. The repulsion between the positively charged protons is lessened by the extra neutrons. The nucleus is held together by nuclear forces.
Electrons in the Gold Atomic Structure
The 79 positively charged protons in gold will be balanced by the additional 79 negatively charged electrons in the metal. Around the nucleus, these electrons will reside in certain orbitals. An electron can only be held in one orbital at a time.
On the periodic table, gold has six energy levels. It is located in period 6. Depending on how much of each orbital can contain, the 79 electrons will occupy the orbitals at these energy levels. The number of electrons that fit in each energy level, from the first to the sixth, may be found using the formula 2n2, where n is the energy level.
First energy level, n = 1, is 2(1)2, meaning it can carry 2 electrons, according to 2n2. Electrons can be held in the first six energy levels in the following amounts: 2, 8, 18, 32, 50, and 72. The electron counts of gold are 2, 8, 18, 32, 18, and 1, and they fill energy levels from lowest to highest because it is an aberration in electron filling. Six concentric rings surrounding a nucleus and the aforementioned number of electrons in each ring can be used to produce a graphic.
Additional information About Gold
Scientists found a solution known as “aqua regia,” which may be used to dissolve gold. This is a combination of hydrochloric and nitric acids, which work as potent oxidants to dissolve gold.
Gold is incredibly soft and flexible. It may be worked into extremely thin sheets; for instance, a single square meter can be covered by pounding a piece of gold the size of a rice grain flat. It is even possible to create gold that is sufficiently thin to have some transparency.
The way the number of atoms in gold link to one another determines all of these characteristics of gold. The strong bonds that bind gold atoms together prevent tarnishing and reactions with other elements. The strong bond between the molecules of gold gives it its malleability and excellent conductivity. Because of its very mobile and dense electrons, gold also gleams when light reflects off of it.
What is pure Gold ?
A typical way to define how pure gold is, is to use the carat system. Pure 24 carat gold is the purest kind of gold. A carat of gold is seventy-five percent gold or eighteen parts gold and six parts metal. Although it is impossible for gold to be 100% pure in reality, there is a very modest permissible impurity level of 0.01%. The Perth mint in Australia produced the purest known sample of gold, which tested positive for purity at 999.999 percent.
Types of Gold Carats
The Arabic term for the carob tree seed is where the word “carat” originates. The carob seed was used to weigh gold in the days before standard measures were established because people mistakenly thought all seeds had the same weight. 24 carats of gold were used to represent one pure gold coin, as it was believed to weigh the same as 24 carob seeds.
1. Alloys of Gold
An alloy can be created by melting gold and combining it with other metals or substances. This imparts the properties of both materials to the alloy. One can strengthen another metal by combining it with gold to create an alloy that is durable enough for daily usage.
Ancient societies that mastered the art of crafting gold alloys included Egypt and Greece. For jewelry and ornamentation, they mixed gold with other metals to produce vividly colored alloys. For example, iron and gold combined to form a striking burgundy red metal.
These days, typical alloys include rose gold and white gold. Silver, palladium, platinum, and nickel are examples of white metals that are combined with gold to create white gold. An alloy with a nickel and gold mixture is hard and robust, whereas an alloy with platinum and gold is hefty and long-lasting.
Copper and gold are used to make rose gold. The alloy turns a deeper crimson the more copper there is in it. In the 1800s, rose gold gained such popularity in Russia that it was dubbed Russian gold.
A variety of colors may be achieved by combining gold with other metals and substances to create alloys, including blue, gray, green and purple.
Because of its nature, gold may be easily separated from alloys. Since gold is non-reactive, it is possible to heat an alloy of gold and salt together to cause the other metals to burn out or absorb, leaving just pure gold.
2. Synthetic gold
It is feasible to produce synthetic gold. By subjecting mercury to a neutron bombardment in 1924, a Japanese researcher created gold, but the resultant material was radioactive. Since then, researchers have experimented with radioactivity irradiating platinum and mercury in a nuclear reactor and converting bismuth to gold using a particle accelerator.
The issue is that the fusion of dying stars releases enormous amounts of heat and energy, which is how gold is made. A supercollider could help us duplicate some of those circumstances, but it would cost too much and take too long to generate enough metal to be a practical supply of gold.
Reclamation of Gold
Instead than using artificial experiments or mining, there is another way to obtain gold. One growing source of gold is the reclamation of previously utilized gold. Gold is frequently utilized in the electronics sector in addition to jewelry.
Due to its excellent conductivity and non-tarnish nature, gold is utilized in wiring and circuit boards. As a result, outdated electronics like laptops and cell phones are becoming a significant source of gold that may be recovered. For instance, Apple was able to recover almost 2000 pounds of gold in 2015 from iPhones that shattered.
Recycling gold that has previously been used is currently more cost-effective and ecologically beneficial than extracting new gold through mining.
