What is the material with the highest specific weight?

 The wonders of nature are profound and include the materials with the highest specific gravity, commonly referred to as the densest materials on Earth. In this piece, we'll explore some of the densest elements on the periodic table, their unique densities, and their astonishing scientific and industrial uses.

Osmium: The Material Boasting the Highest Specific Weight

Osmium, a metal in the Platinum group, boasts the highest specific weight, weighing approximately 22.661 grams per cubic centimeter. This element, symbol "Os" and atomic number 76, derives its name from the Greek word osmè, translating to "smell," referring to the sharp scent of one of its oxidized compounds. While Osmium's brittleness can make it challenging to handle, it's often alloyed with other metals to enhance its hardness and resistance to wear. The jewelry industry appreciates Osmium for its capacity to create durable coatings, whereas the electronics industry employs its high density for precision components.

Osmium participated in the creation of the original platinum-iridium cylinder defining the sample kilogram, replaced in 2019 by a definition based on Planck's constant. This alteration made the kilogram a more precisely defined unit of measurement.

Iridium: A High-Density Material

Iridium, a transition metal and part of the Platinum family on the periodic table, bears the symbol "Ir" and atomic number 77. Its name originates from the Greek word iris, meaning "rainbow," due to the various colors it displays when oxidized. Iridium, one of Earth's heaviest metals, has a specific gravity of roughly 22.650 grams per cubic centimeter, slightly lower than Osmium. This hard, brittle, silvery-white metal finds use in several industrial applications, primarily alloyed with other metals to enhance their performance. The jewelry industry commonly uses Iridium, alloyed with Platinum, to craft fine jewelry due to its luster and wear resistance. It also finds application in aerospace, and for creating durable electrical contacts and watch parts.

Platinum: A Dense and Adaptable Metal

At approximately 21.45 grams per cubic centimeter, Platinum ranks among Earth's densest metals. Known as one of the most valuable and recognizable transition metals, Platinum (symbol "Pt" and atomic number 78) is prized for its resistance to corrosion and oxidation, leading to its use in numerous applications. Notably, it's used in the production of catalysts for the chemical and automotive industries. Further, it plays a crucial role in the jewelry industry, where its sparkle and strength make it ideal for crafting fine jewelry. Interestingly, Platinum is rare in the Earth's crust, making it difficult to find in substantial quantities. It is estimated that the quantity of Platinum mined is significantly less than that of other precious metals like gold and silver.

Heavy elements: specific weight and atomic weight

In addition to the materials with the highest specific gravity, it is worth exploring the world of atomic elements to understand which single atom has the highest atomic weight. From this point of view, the natural element with the highest atomic weight is uranium, with a mass number of 238. However, if we also consider man-made elements, two contenders for first place emerge. These are lawrencium and hahnium, which both have a mass number of 260. This value represents the total number of particles contained in the nucleus of the atom, that is, the sum of protons and neutrons.

There are unstable nuclei both in nature and as a result of experiments in nuclear accelerators, which can reach atomic weights estimated as high as 280-285 UMA (atomic mass units). However, most of these unstable nuclei still have no official name and are subject to scientific research. Interestingly, the material with the highest mass per unit volume, thus the "heaviest," does not coincide with the material with the highest atomic weight. In fact, Osmium has an atomic weight of 190 UMA but a density of 22.661 grams per cubic centimeter, giving it the title of metal with the highest specific gravity on Earth. This characteristic is due to the different way atoms compact in forming matter.