Gold is one of the chief desirable objects that the entire mankind yearns to own. But what makes this golden yellow substance a must-have for all? To know this, we shall see some chemical properties of one of the most precious metals in the world – gold.
Crawling like ants on the rocks below
The men will steal, the men will dream
And die for gold on the rocks below
Gold, Gold, Gold, they just gotta have that gold
Gold, Gold, Gold, they’ll do anything for gold
You must have recognized these lines from the famous 1969 western movie Mackenna’s Gold. These lines aptly describe the craze one had for this shining yellow metal. Many a men have given up their lives in their quest for gold and many a countries have gone into battle to save their gold.
In the world of Chemistry, gold is represented by the symbol ‘Au’. But the original name is Aurora which used to be the name of a Roman deity. She was known as the ‘Goddess of the dawn’. The unit for the measurement of gold is ‘Carat’. Pure gold is 24 carat. 23 carat is 96.5% gold.
The word carat originated from the carob seeds which were used in ancient Asian gold markets as weighing scales.
Properties of Gold
The term gold comes from a Latin word aurum, that means shining dawn. This Latin term gives rise to its chemical symbol Au. The following table will cover some of the general properties of the element gold.
| General Properties of Gold | |
| Chemical Symbol | Au |
| Atomic Number | 79 |
| Elemental Characteristic | Transition metal |
| Elemental group, period and block | 11, 6, d |
| Melting Point | 1337.33 K |
| Boiling Point | 3129 K |
| Isotopes | 1 |
| Electrochemical Equivalent | 2.4496g/amp-hr |
Occurrence in Nature
Gold has a wide distribution within the earth, especially in areas under the oceans and sea. It is found in the form of dust, grains, flakes, or nuggets. The chemical element of gold occurs by amalgamation of mercury and silver. It also forms telluride minerals in its compound form with tellurium.
Physical Properties
Before going through the chemical properties, let us have a look at the physical properties of gold. Gold is ductile as well as malleable in nature. This means it can be drawn into wires and beaten into thin sheets. This soft metal is able to reflect heat as well as light. Gold is a metal and therefore a good conductor of electricity.
Chemical Properties
As we go into the details of chemical properties of gold, you will understand the connection between the general and physical properties discussed above. Gold is considered to be a noble metal. It is chemically inactive. This is because it is highly resistant to react with other elements. The oxidation state of gold ranges from -1 to +5. The +1 and +3 [Au(I) and Au(III)] are the most common oxidation states of gold. Gold tends to form an amalgamation with mercury instead of reacting to create new compounds. It is resistant to the effect of most acids and therefore does not corrode easily. Gold can however be affected by 3:1 mixture of hydrochloric acid and nitric acid, called aqua regia. So, generally speaking gold is not a highly reactive compound. Apart from acids, gold does not combine with oxygen, halogens, etc. easily. Aurous (univalent) and auric (trivalent) are two types of compounds formed by gold.
Gold is a very good conductor of heat and electricity. Therefore, it is made into thin wires and used in connecting electrical circuits. It is also used to apply a thin film on windows of sky scrappers to reflect sun rays due to its ability to reflect heat as well as light. Copper components are protected and their solderability is improved by using gold electroplating in copper industries.
Uses of Gold
The most common uses of gold is for making gold jewelry. It is also used to make glass that have red or purple colors. Electronic products like computers, telephones, and home appliances, industries, medical field, etc. all have some or the other uses of gold. Gold coins were very popular in the ancient world.
This metal looks attractive and is virtually indestructible. Hope the above information on chemical properties of gold element helps you understand this metal better.