There are two possible ways to determine the “heaviest” element – based on its density or atomic mass.
The heaviest element in terms of density can be defined as mass per unit volume, which is usually measured in grams per cubic centimeter or kilograms per cubic meter.
The most naturally occurring element on Earth is Osmium.
Another way to look at weight is in terms of atomic weight, the average mass of atoms of an element.
This is a fundamental concept in chemistry because most chemical reactions occur according to simple numerical relationships between atoms.
Below, we have listed the seven heaviest elements found on Earth according to their atomic mass.
Note: We have not mentioned elements whose properties are unknown or unconfirmed, such as moscovium, flerovium, nihonium and meitnerium.
Rutherfordium (Rf) was the first superheavy element discovered [in 1964].
It is highly radioactive, and the most stable isotope 267Rf has a half-life of about 78 minutes.
Rutherfordium is a synthetic element created in a laboratory by bombarding Californium-249 with Carbon-12 nuclei.
A total of 16 isotopes have been reported with atomic masses between 253 and 270.
The element is expected to be solid under normal conditions and is thought to have similar chemical properties to hafnium.
It is only created in small quantities and used for scientific research only.
Dubnium (Db) is a radioactive element, first synthesized in 1968 at the Joint Nuclear Research Institute, Russia.
It has seven recognized isotopes, the most stable of which is 268Db with a half-life of 32 hours.
Dubnium can be produced by bombarding either californium-249 with nitrogen or americium-243 with neon.
Limited examination of Dubnium’s chemistry has confirmed that the element behaves more like niobium rather than tantalum, breaking the periodic flow.
Since the element is not found free in nature or created in bulk quantities in a laboratory, it has no application other than scientific research.
The research team bombards californium-249 with oxygen-18 nuclei to produce seaborgium-263.
It is a radioactive element whose most stable isotope (269Sg) has a half-life of about 14 minutes.
Only a few atoms of seaborgium were ever produced, and their use was solely for scientific research.
The little research that has been carried out on this synthetic chemical element shows that seaborgium is a solid heavy metal under normal conditions.
In 2014, Japanese researchers established a chemical bond between carbon atoms and seaborgium for the first time, opening a new door to analyze the effects of Einstein’s relativity on the structure of the periodic table.
Bohrium (Bh) is an artificially produced radioactive element named after the famous physicist Niels Bohr.
Because it decays so quickly through alpha particle emissions (270Bh has a half-life of 61 seconds), it is extremely difficult to study the element.
Bohrium is not found in nature, and only a few atoms have been produced so far.
Discovered by German physicists in 1984, Hassium (Hs) is one of the heaviest and most dense elements in the periodic table.
All nine isotopes of the element have very short half-lives: the most stable (270Hs) has a half-life of 10 seconds.
So far, only a few hassium atoms have been produced.
Although the exact melting point, boiling point and density are not confirmed, the element is believed to be solid at room temperature.
These radioactive transition metals may react with other elements [of their group] if produced in bulk quantities.
For now, it has no commercial use other than scientific research.
Tennessine (Ts) is the second heaviest known element discovered by a Russian-American collaboration in 2010.
It is an artificially produced radioactive element.
Tennessine is produced by combining calcium-48 with berkelium-249.
The use of tennessine is limited to research purposes due to its very small production.
Its most stable isotope (294Ts) has a half-life of about 80 milliseconds, which decays through alpha decay.
Read: 15 Densest Materials on Earth | Volumetric Mass Density
First synthesized in 2002, Oganesson (Og) is the heaviest element on the periodic table.
This highly radioactive element is a member of the noble gas group.
As of 2005, only six Oganesson atoms have been identified.
Since Oganesson is very unstable (with a half-life of about 0.89 milliseconds) and does not occur naturally, there is almost no reason to consider it a health hazard.
Heaviest Naturally Occurring Element: Uranium
Uranium glass glows under ultraviolet light | Credit: Wikimedia Commons
Atomic mass: 238.0289
Atomic mass: 238.0289
Atomic mass: 238.0289
Atomic mass: 238.0289
Atomic mass: 238.0289
Atomic mass: 238.0289
Atomic mass: 238.0289
Atomic mass: 238.0289
Although uranium is a radioactive element, its rate of decay is much slower than other elements associated with radioactivity.
Its most natural form (uranium-238) has a half-life of about 4.5 billion years.
Read: 15 Interesting Facts About Uranium | Weak Radioactive Metals
Uranium is mostly used as nuclear fuel to produce electricity in nuclear power stations.